CHANGELOG

v2.19.1

Web Terminal

Clear button now drops server-side history: previously only cleared the visible UI; on reconnect/refresh the old ring buffer would replay
- New REST endpoint GET /terminal_clear resets the ring buffer (writePos/wsSentPos to 0)
- Frontend awaits server clear, then _xterm.reset() for a clean state (cursor at 0,0, SGR reset)
Keyboard shortcuts in view-only mode: standard browser-like behavior when input is disabled
- Ctrl+C / Ctrl+Insert — copy selection to clipboard
- Ctrl+A — select entire scrollback
- In input mode all keys pass through unchanged (Ctrl+C → SIGINT to UART)
- Implemented via attachCustomKeyEventHandler — xterm scrollback navigation (PageUp/PageDown) preserved

v2.19.0

New Feature

Terminal protocol optimization: Full web terminal for UART devices
- Raw parser with 5ms flush timeout — no line buffering, instant echo
- Ring buffer in PSRAM 32 KB (S3) / internal RAM 4 KB (MiniKit) with history replay
- WebSocket endpoint /ws/terminal for real-time bidirectional streaming
- ANSI rendering via xterm.js with fit addon (dynamic toggle, lazy loaded)
- Web keyboard input: browser → WebSocket → UART TX (toggle button, ANSI mode only)
- Fullscreen mode, save/copy/clear buttons, partial line display
- Use case: headless device diagnostics, remote serial console (e.g. RPi over WiFi)
RC Monitor: MAVLink source: RC channel bars in web UI now work with MAVLink protocol
- Parses RC_CHANNELS (msg 65) from FC and RC_CHANNELS_OVERRIDE (msg 70) from GCS/plugin
- Passive extraction from traffic passing through the bridge (any direction, any interface)
- Uses shared RcChannelData — same web UI monitor as SBUS/CRSF, no additional polling

MP Plugin (v2.3.0)

R2D2 format support: Auto-detect $ prefix (EdgeTX raw -1024..+1024, 24ch) alongside existing RC format
- Converts raw values to PWM, uses first 16 channels
- Detected format shown in LED tooltip: "Connected, data OK (R2D2)" or "(ESP)"
- Unknown format indication: "Connected, unknown data format"
Rate limiter: Selectable RC Override rate (10/20/30/40/50 Hz, default 20)
- Applies on the fly, no reconnect needed
- Setting persisted in MP config.xml
RST checkbox: Reset ESP via RTS toggle on COM connect (for CP2104/CH340 boards stuck in bootloader)
- Visible only in COM mode (hidden for UDP/BLE)

Web Flasher

Try Reboot button: Reset ESP via RTS toggle (CP2104/CH340 boards only)

Docs

README: Added RC-Connector as alternative to RC Override plugin
README: ELRS telemetry section updated — covers UDP, BLE, and USB output paths

v2.18.15

New Feature

CRSF/ELRS Protocol Support (Phase 1): Device 1 CRSF Input mode for ExpressLRS receivers
- CrsfParser: frame validation (sync address, length, CRC8 DVB-S2), RC channels + telemetry
- D1_CRSF_IN: UART1 at 420000 baud, 8N1, non-inverted (single RX wire)
- D2_USB_CRSF_TEXT: text output via USB — RC, LQ, BAT, GPS, ATT, FM, ALT
- CRSF/ELRS Statistics in web UI (valid frames, invalid frames, CRC errors, last activity)
- Three-mode architecture: UART Bridge / SBUS / CRSF — mutually exclusive on Device 1
CRSF Text Outputs (Phase 1.5): UDP and BLE output for CRSF text data
- D4_CRSF_TEXT: CRSF text via UDP (all frame types, compatible with RC Override plugin)
- D5_BT_CRSF_TEXT: CRSF text via BLE (S3 boards only)
- Per-output independent RC rate limiting (telemetry passes unrestricted)
- Generic sendDirect() path in UdpSender (non-SBUS data bypasses SBUS batching)
CRSF Binary Output (Phase 2): Raw CRSF frame forwarding via USB and UART3
- D2_USB_CRSF_BRIDGE: binary CRSF frames via USB (no rate limiting)
- D3_CRSF_BRIDGE: binary CRSF frames via UART3 at 420000 baud
- sendRawToOutputs() in CrsfParser: forwards raw frames before buffer consume (zero-copy)
CRSF Bidirectional Bridge (Phase 3): Reverse channel for telemetry back to ELRS RX
- Device 1 CRSF_IN: TX pin enabled for bidirectional UART (was RX-only)
- Device 3 CRSF_BRIDGE: RX pin enabled for bidirectional UART3 (was TX-only)
- USB/UART3 → RawParser → Uart1Sender reverse flows (raw passthrough)
CRSF Text Filters (Phase 4): Per-frame-type bitmask filter for text outputs
- 6 filter groups: RC Channels, Link Stats, Battery, GPS/Altitude, Attitude, Flight Mode
- Select All checkbox with 3x2 grid layout in web UI
- Applied to text outputs only (USB, UDP, BLE) — binary bridge passes all frames unfiltered
USB Logger (D2_USB_LOG): New Device 2 role — log output via USB Serial
- Same format as UART3 Logger: [timestamp][LEVEL] message
- Shares log level setting with UART Logger (USB/UART Logs)
- USB Device mode only (Host mode ignored for logger)
- Non-blocking write with availableForWrite() check
- Can work simultaneously with D3_UART3_LOG (independent devices)
RC Channel Monitor: Real-time 16-channel bar visualization for SBUS and CRSF input
- Collapsible section with on-demand polling (250ms), zero overhead when collapsed
- Shared RcChannelData storage written by SBUS/CRSF parsers, read by /api/rc/channels API
- Stale indication (gray bars) when no signal for >2 seconds
- Two-column grid layout with center line at 1500µs (neutral position)

Improvement

Unified output rate field: renamed sbusRate → outRate across all devices
- Shared by SBUS Text and CRSF Text output modes
- Backwards-compatible config loading (old device2_sbus_rate key still accepted)
UI role constraints: incompatible device roles auto-disabled when Device 1 is in input mode
- D2 plain USB and UART2 blocked when D1 = SBUS_IN or CRSF_IN (no telemetry flow)
- D3 Mirror and Bridge blocked when D1 = SBUS_IN or CRSF_IN
- Automatic cleanup resets dependent roles when D1 mode changes
Custom baudrate UI: select dropdown with "Custom" option + text input for arbitrary values (e.g. 420000)
UART Config display: shows actual protocol parameters (SBUS: 100000/8E2, CRSF: 420000/8N1) instead of user config
UDP Batching auto-control: forced ON for SBUS UDP, forced OFF for CRSF Text UDP (role-dependent)
Network Logs selector: restricted to D4_LOG_NETWORK role only (was enabled for all D4 roles)
Removed duplicate Send Rate from Advanced Configuration (already in device table)
Per-board log buffer sizes: MiniKit 30/25, S3 with BLE 50/40, S3 without BLE 100/95

Bug Fix

Device 2 Pins column: USB-based roles (USB Logger, USB CRSF Text, USB CRSF Bridge) now correctly show "USB" instead of "N/A"
RTS/CTS display: hidden in System Status when Device 1 is in SBUS/CRSF mode (not applicable)
sys_evt stack overflow crash: Increased CONFIG_ESP_SYSTEM_EVENT_TASK_STACK_SIZE from 2304 to 3072
- Root cause: log_msg() stack buffers (~600B) + WiFi/mDNS events exceeded default 2304B stack
- Crash was intermittent — FreeRTOS only detects overflow on context switch
- Applied to all 18 sdkconfig files
alpine:initialized event timing: Fixed initialization after Alpine.js 3.15.8 upgrade
- Event fires during deferred script execution (before DOMContentLoaded, not after)
- System Status showed "Uptime: 0s", "Free RAM: 0" until Protocol Statistics was toggled
BLE crash on pioarduino 3.3.7: ESP32-S3 BLE initialization caused boot loop (LoadProhibited)
- Framework 3.3.7 extended btInUse() check to NimBLE — released BT memory before setup()
- Fix: #include "esp32-hal-bt-mem.h" sets _btLibraryInUse via constructor before app_main()
MiniKit BLE regression in ESP-IDF 5.5.2: BLE connections broken on ESP32 WROOM (MiniKit)
- pioarduino 3.3.6+ (ESP-IDF 5.5.2) broke BTDM controller — NUS characteristics inaccessible after pairing
- Pinned to pioarduino 3.3.5 (ESP-IDF 5.5.1) until fix available in ESP-IDF 5.5.3
Hostname case inconsistency: AP SSID changed from mixed case to lowercase after saving settings
- Removed toLowerCase() from hostname save handler (mDNS is case-insensitive per RFC 1123)
- Unified hostname generation to mixed case (ESP-Bridge-XXXX) across mDNS, AP SSID, BLE/BT name

Web Interface

Full Alpine.js migration: CrashLog moved from innerHTML/DOM to Alpine store + x-for template
- Deleted crash-log.js and form-utils.js (legacy JS files)
- Expandable panic details, copy backtrace/addr2line — all in Alpine store
Fixed double initialization: body x-init and DOMContentLoaded both called init/startPolling
- Caused duplicate fetch intervals; now initialization runs once via alpine:initialized
SBUS polling reactivity: replaced x-effect on body with Alpine.effect() in init block
Cleaned utils.js: removed dead code (safeFetch, formatBytes, formatUptime)
Alpine.js updated: 3.15.4 → 3.15.8

Code Cleanup

Removed obsolete SBUS multi-source detection code (superseded by SbusRouter)
Removed dead shouldFlushNow/getBatchTimeoutMs methods from parser classes
Fixed misleading comments (SBUS output flow, LED monitor task)

Diagnostics

SysEvt stack monitoring: Added sys_evt task to stack watermark diagnostics

Documentation

Help page: Added Device 2 and Device 3 role descriptions (previously only Device 4/5 were documented)
README: Added USB Logger to Device 2 roles

Build & Release

GitHub Actions fix: Changelog extraction regex now matches version headers without description suffix
Collapsible release notes: ### sections auto-wrapped in <details> blocks on GitHub releases

v2.18.14

Web Interface

mDNS navigation: Captive portal redirects to {hostname}.local instead of raw IP
- Smart reconnect after Save: 3 retry rounds (5s countdown + parallel probe)
- Probes mDNS target URL and current origin in parallel (Promise.any), first wins
- Handles hostname changes: probes new .local name, skips stale cached old name
- Fallback UI: clickable links (mDNS, current IP, 192.168.4.1) after 3 failed attempts
- URL-aware logic: mDNS reconnect only when browsing via .local, IP mode uses simple reload
- Factory reset: shows alert with default AP name (MAC-based), captive portal handles reconnect
defaultHostname in API: MAC-based hostname (esp-bridge-XXYY) always available from /api/status
Mobile responsive fixes: Frequency dropdown overflow fixed (w-80), compact table cells and font sizes on small screens, WiFi mode dropdown width constrained
Browser time sync for crashlog: Real date/time in crash log entries
- Browser sends epoch on page load (/api/time), ESP tracks via millis() delta
- Once per boot sync, survives in RTC until next reboot
- New "Date" column: YYYY-MM-DD HH:MM (local timezone) or — if no sync

LED Indication

BLE + WiFi combined modes: Visual feedback for all connection states
- RGB LED (Zero, SuperMini): Color fade animation for combined modes
  - WiFi AP + BLE: Blue↔Purple fade (~2s cycle)
  - WiFi Client + BLE: Green↔Purple fade (~2s cycle)
  - BLE only: Static purple
- Single-color LED (XIAO, MiniKit): Simplified "solid = working, blink = problem"
  - Stable states (AP, Client, AP+BLE, Client+BLE): Solid ON
  - BLE only (no WiFi): Fast blink (150ms)
  - WiFi transient states always visible (searching/error blinks)
New LED modes: LED_MODE_BLE_ONLY, LED_MODE_WIFI_AP_BLE, LED_MODE_WIFI_CLIENT_BLE
Coordination API: led_set_wifi_mode() and led_set_ble_active() for combined state management
Code cleanup: Removed unused blink patterns (BLINK_WIFI_CLIENT, BLINK_DOUBLE, BLINK_TRIPLE) and timing constants

Web Interface

Device 5 (BLE) statistics: TX/RX byte counters in Device Statistics panel
- Shows only when Device 5 role is active (SBUS_OUT_TEXT or SBUS_OUT_BIN)
- Tracks both sendDirect (fast path) and queue-based transmissions
SBUS Fast Path fix: Last Activity and Success Rate now work correctly
- Added lastFrameTime tracking to SbusFastParser (was always showing "Never")
Unified device naming: AP SSID now uses mDNS hostname (one name everywhere)
- "Device Name" field (max 32 chars) sets: mDNS hostname, AP SSID, BLE device name
- AP SSID field is read-only, auto-filled from Device Name
- Simplifies configuration: one name = one device identity

BLE Support

NimBLE NUS: BLE Nordic UART Service for all boards (BLE_ENABLED flag)
- Build environments: zero_ble_*, supermini_ble_*, xiao_ble_*, minikit_ble_*
- GATT server with NUS TX (notify) and RX (write) characteristics
- WiFi + BLE coexistence confirmed on ESP32-S3 (heap ~36KB min) and ESP32 MiniKit (heap ~16KB min)
Security: Just Works pairing with bonding (no PIN prompt)
- GATT characteristics require encryption + authentication
- Bond persistence in NVS (up to 10 bonds), repeat pairing auto-handled
- Changed from PIN pairing due to Android compatibility issues with static passkey
MiniKit BLE: NimBLE ported to ESP32-WROOM-32 (BLE-only controller mode)
- Separate sdkconfig with LWIP/WiFi memory optimization for low-RAM environment
MP Plugin (RcOverride_v2_BLE): BLE device scan/select/connect via WinRT API (compiled as DLL)
- Device list filtered by NUS service (only paired ESP-Bridge devices shown)
- LED tooltips: hover shows status (Disabled, Connecting, Connected data OK, no telemetry, etc.)
- BLE auth failure detection: stops retries on pairing rejection (DarkRed LED)
- BLE device list auto-refresh on first switch to BLE mode
- General failure counter (5 consecutive failures → stop retries)
- Proper BLE cleanup (service dispose, notification unsubscribe)
- Settings persistence: Source type (COM/BLE/UDP), port, device ID saved to MP config.xml
- Auto-scan on load: BLE devices scanned automatically if BLE mode was saved
- espFix: Handshake.RequestToSend during port Open() prevents ESP32-S3 USB Serial/JTAG reset
  - Root cause: ARDUINO_USB_MODE=1 (HWCDC) has hardware auto-reset on RTS transition
  - Same approach as MissionPlanner's CHK_rtsresetesp32 setting
  - Applied to both v2 (COM/UDP) and v2_BLE plugins
MP Plugins crash fix: Image disposal (ArgumentException in Image.get_RawFormat)
- VideoTX_Perun: clone MP resources instead of direct use, dispose in Exit()
- FuseSwitch_Perun: dispose icon in Exit()

Code Cleanup

BLE+WiFi coexistence: Always enabled, mutual exclusion removed. Fallback skip commented in device_init.cpp
BLE diagnostics: Replaced forceSerialLog with log_msg at appropriate levels
Removed: ble_dump_bonds() debug function, BLE_WIFI_COEXIST_TEST flag
Heap monitor: Disabled by default, kept under #ifdef DEBUG for quick re-enable
Build flags: -D DEBUG commented out in all builds (uncomment for forceSerialLog)
Merged diagnostics: systemDiagnostics() + runAllStacksDiagnostics() → single function (10s interval)
- One log line: stacks + heap (free/total/min) + MaxBlock + PSRAM + memory thresholds

Build & Release

GitHub Actions: Release includes bootloader.bin, partitions.bin, firmware.bin + .elf for each board
BLE builds added: zero-ble, supermini-ble, xiao-ble, minikit-ble (9 builds total)
New sdkconfig files: supermini_ble_*, xiao_ble_* (production + debug)

WiFi

WiFi AP Mode: Temporary mode (new default)
- New WifiApMode enum: DISABLED, TEMPORARY, ALWAYS_ON
- TEMPORARY: WiFi starts at boot, auto-disables after 5 min with no clients
- Timer cancelled when client connects, restarted when last client disconnects
- Config migration from old permanent boolean field
- Prevents lockout when ESP inside TX module bay (buttons inaccessible)
WiFi Stage 2: Full memory release on temporary mode timeout
- wifiStop() now performs complete cleanup: webserver, UDP, DNS, mDNS, esp_wifi_deinit, esp_netif_destroy
- Frees ~50 KB (tested: 69K → 120K free heap on S3 Zero BLE)
- One-way shutdown (reboot required to re-enable WiFi) — fits "save = reboot" model
- Fixed disableAllTasks() → disableNetworkTasks(): was incorrectly disabling standalone tasks

Fixes

SBUS Fast Path statistics display: With multiple SBUS inputs, web UI showed stats from first parser (Device 1) even if inactive
- SBUS routing and data flow worked correctly — only statistics display was affected
- Now picks most recently active parser by lastFrameTime
WiFi Client + Temporary timeout: Timer was killed on IP_EVENT, browser polling couldn't restart it
- WiFi never auto-disabled in Client mode with "At Boot: Temporary"
- Fix: restart timer on IP event, resetWiFiTimeout() now uses startWiFiTimeout() (re-enables disabled timer)
Device 5 (BLE) build fix: device5_config references in populateApiStatus missing #ifdef BLE_ENABLED guard
Crashlog date column: Wider Date field (22% → 26%) for full datetime display
WiFi Client mode stability:
- Race condition fix: don't change state to CLIENT_NO_SSID if already connected
- wifiStopping flag prevents event handler work during WiFi stop (crash fix)
- AP client connect/disconnect event handling improved
WiFi event handler crash fix: Replaced blocking vTaskDelay() with esp_timer for reconnect retry
- Root cause: vTaskDelay inside event handler blocks sys_evt task with mutex held → assert failure
- Crash manifested as IllegalInstruction at 0x00000000 when WiFi Client mode without AP available
Crashlog hardening: RTC variable validation, ASCII string checks, JSON re-serialization
embed_html.py: Removed cssmin dependency, simplified to gzip-only compression
Boot optimization: Skip 500ms delay on normal boot (no click detected)
Memory diagnostics: New format HEAP: free/total (min=X) | PSRAM: free/total

v2.18.13

MiniKit Build Split

BT/no-BT variants: MiniKit now has separate builds
- minikit_bt_* — with Classic Bluetooth SPP
- minikit_* — without Bluetooth (more free RAM for WiFi)
New flag: MINIKIT_BT_ENABLED for conditional BT compilation

Build System

sdkconfig reorganization: Moved to sdkconfig/ directory for cleaner structure

Web UI Fixes

Flow Control checkbox: Fixed auto-enabling bug (string '0' was truthy)
Type consistency: All select/number fields now use strings for Alpine.js x-model compatibility
MAVLink Routing checkbox: Fixed visibility when switching to MAVLink protocol
Dirty checking: Fixed false positives from type mismatches (string vs number)
Crash History: Fixed "Loading..." text centering

v2.18.12

Web UI

Alpine.js refactoring: Complete rewrite using Alpine.js framework
- Reactive stores for app config, status, SBUS, crash history
- Cleaner code: 97 getElementById calls → ~15
- Split API: /api/config (static) + /api/status (polled)
- JSON body for POST requests (was form-urlencoded)

SBUS Conversion

OpenTX/EdgeTX compatible formula: SBUS→µs conversion now matches radio display
- 172 → 988µs, 992 → 1500µs, 1811 → 2012µs (was 1000-2000 Betaflight-style)

MiniKit LED

BT connection indicator: LED blinks when Bluetooth SPP client connected
- Distinguishes from WiFi mode (solid LED)

v2.18.12-prev

New Features

SBUS Output Format Selector: Dropdown with Binary/Text/MAVLink options
MAVLink RC_CHANNELS_OVERRIDE: SBUS→MAVLink conversion for wireless RC control
UDP Send Rate: Configurable 10-70 Hz for SBUS UDP Output
UDP Source Timeout: Configurable 100-5000 ms for SBUS Input role
BT Send Rate: Configurable 10-70 Hz for Bluetooth SBUS Text output

MiniKit Bluetooth

Bluetooth SPP Bridge: New Device 5 with two roles
- BT Bridge — MAVLink/Raw telemetry output
- BT SBUS Text — text format for RC Override plugin
- SSP "Just Works" pairing (no PIN prompt)

MiniKit Memory Optimization

DMA buffers reduced: 2x smaller for MiniKit (16KB vs 32KB on S3)
Auto Device1 SBUS_IN: When any device has SBUS role, Device 1 auto-switches to SBUS_IN
- Saves ~14KB RAM (minimal DMA buffers instead of full UART bridge)
- UART bridge is unused in SBUS mode anyway
SBUS→MAVLink conditional: Disabled by default to save memory (uncomment -D SBUS_MAVLINK_SUPPORT in platformio.ini to enable)

MiniKit Fixes

Fix spurious WiFi reset: Disabled floating GPIO0 button handling
Quick reset always forces AP: Triple RESET guarantees Web UI access
Fix Device 3 role validation: SBUS_IN role was blocked by incorrect validation
Fix BT SBUS Text output: Buffer size was too small (64 < 101 bytes needed)
Fix SBUS validation: Added D3_SBUS_IN and D5_BT_SBUS_TEXT to validation
Fix SBUS + WiFi crash: Reduced DMA buffers for all SBUS devices (512/0/1024 vs 4096/4096/8192)
- Root cause: Large buffers caused heap fragmentation, WiFi tcp_accept failed

Code Quality

SBUS conversion buffer refactored: Lazy allocation in SbusRouter singleton
- Memory saved when SBUS output conversion not used (~101 bytes)
- Removed global g_sbusConvertBuffer variable

Web UI

Device 4/5 configuration: Renamed roles, MiniKit-specific options
Modular JS architecture: Reduced code duplication
BT Send Rate slider: Rate control for SBUS Text output (Device 5)
Auto Device1 role: Device 1 automatically set to SBUS_IN when SBUS role selected on other devices
SBUS Output roles refactored: Split into "SBUS Output" (binary) and "SBUS Text Output" for Device 3/4
- Format selector dropdown replaced with composite role values
- Rate selector shown only for Text output modes
Device 5 roles renamed: "BT Bridge" → "Bridge", "BT SBUS Text" → "SBUS Text Output"
UART roles disabled in SBUS mode: UART2/UART3 Bridge options disabled when Device 1 = SBUS Input

Mission Planner Plugin

RC Override Plugin v2.0.1 (plugins/rcoverride_v2.cs):
- COM and UDP sources
- Port open retry with 2s interval (for BT SPP connection delay)
- Lock port/source selection when connected
- Dynamic port list refresh every 3s
- Console diagnostics for debugging
- Fix RC checkbox behavior: LED turns gray and port closes when unchecked
- Fix controls unlock: COM port and Source dropdowns re-enabled when RC disabled

v2.18.11

New Features

WiFi AP Channel: Configurable WiFi channel (1-11) for AP mode via Web UI
SBUS Text Format Output: Optional text format RC 1500,1500,...\r\n for SBUS output roles
- Checkbox "Text format" in Web UI for Device 2/3/4 SBUS outputs
- Use case: Mission Planner RC Override plugin compatibility, debugging
Device 3 SBUS Input: New D3_SBUS_IN role for SBUS input on Device 3 UART pins
- Needed for MiniKit where Device 2 = USB only

Fixes

MiniKit USB Packet Loss: Fixed buffer initialization order — setTxBufferSize() must be called BEFORE Serial.begin() on UART
- Root cause: Default UART TX buffer = 0 (only 128-byte hardware FIFO)
- Result: ~13% packet loss during FTP bursts eliminated
MiniKit USB Block Detection: Disabled for UART (availableForWrite returns constant, causing false positives)
SSID Generation: Fixed logic - empty SSID triggers auto-generation, user-set "ESP-Bridge" is now respected
AP SSID Safety Check: Prevents AP SSID from matching client network names

Documentation

MiniKit CP2104: All documentation updated to specify CP2104 chip (CH340/CH9102 not tested)
README: Full MiniKit board documentation added (connections, quick start, LED, button functions)
Help page: MiniKit pinout table and requirements added

Web UI

SBUS Config Warning: Shows warning when SBUS Output configured without SBUS Input source

ESP32 MiniKit (WROOM-32) Support

New board support: ESP32 MiniKit (ESP32-WROOM-32 based development board)
- PlatformIO environments: minikit_production, minikit_debug
- GPIO mapping: RTS/CTS on GPIO18/19, Device 3 UART on GPIO16/17, LED on GPIO2
- No USB Host support (WROOM lacks USB OTG peripheral)
Quick Reset Detection: Triple RESET for WiFi activation (replaces BOOT button)
- NVS-based detection (RTC cleared on RESET)
- Boot loop protection (crashes clear counter)
Memory Optimizations for ~160KB usable heap (no PSRAM):
- Reduced WiFi buffers in sdkconfig
- Reduced LWIP TCP buffers (IPv6 disabled)
- LOG_BUFFER_SIZE: 30 (vs 100 on S3)
- UART1_TX_RING_SIZE: 4KB (vs 8KB on S3)
- UDP log buffer: dynamic allocation only when needed
Single-color LED support: Active HIGH logic for GPIO2
Web UI: MiniKit board detection, Device 2 options filtered
Help page: MiniKit pinout and documentation added

Web UI

Utils refactoring: JSON parse error handling moved to utils.js
Form utils: Improved radio button and select initialization

v2.18.10

New Features

UDP Auto Broadcast: Automatic broadcast IP detection from DHCP subnet (Client mode only)
Multiple UDP Targets: Support up to 4 comma-separated target IPs

Web UI

Cleanup and fixes
Unified checkbox styling with CSS class

Fixes

mDNS Task Priority: Increased from 1 to 5 for better reliability

Code Quality

EditorConfig added
Release changelog extraction fix
Code comments cleanup

v2.18.9 (WiFi & Configuration Improvements)

WiFi Enhancements

Multi-WiFi Networks Support: Configure up to 5 WiFi networks with priority order
- Automatic fallback to next network when connection fails
- Priority-based scanning (tries networks in configured order)
- Web UI with dynamic network list management (Add/Remove buttons)
- Backward compatible: existing single-network configs auto-migrate to new format
- Config version upgraded to v10 with automatic migration
Unique WiFi AP Name: Auto-generated AP SSID with MAC suffix (e.g., ESP-Bridge-11fc)
- Prevents AP name conflicts in multi-device environments
- Generated on first boot, saved to config
Configurable mDNS Hostname: User can set custom .local address
- Works in both AP and Client modes
- Auto-generated on first boot (e.g., esp-bridge-11fc)
- Web UI field with validation (a-z, 0-9, hyphen only)
mDNS in AP Mode: Added mDNS support for Access Point mode (was Client-only)
Connected Network Display: System status now shows actual connected network name in Client mode

Web UI Improvements

Auto-Reconnect after Save & Reboot: Page automatically reconnects after device reboot
- 8-second countdown during reboot
- Up to 30 reconnection attempts with progress indicator
- Automatic page reload when device comes back online
Button Alignment: Centered Configuration Backup and Firmware Update buttons
Consistent Hint Styling: Standardized hint text formatting across all sections

Configuration Management

Factory Reset: New web UI button to reset all settings to defaults
WiFi Reset via BOOT Button: 5-second hold resets WiFi settings only (not full config)
- Resets: mode, SSID, password, client credentials, mDNS hostname, TX power
- Preserves: UART settings, device roles, protocol settings
Config Export Filename: Now uses mDNS hostname (e.g., esp-bridge-11fc-config.json)

Code Quality

WiFi TX Power Constant: Added DEFAULT_WIFI_TX_POWER define (was magic number)
WiFi Reset Function: Extracted config_reset_wifi() for code reuse

v2.18.8 (Build Automation & Code Cleanup)

CI/CD Improvements

GitHub Actions Multi-Board Build: Automated firmware build for all supported boards
- Builds zero_production, supermini_production, xiao_production in single workflow
- Creates unified release zip with firmware.bin and firmware.elf for each board
- Automatic GitHub Release creation on tag push
- Release notes extracted from CHANGELOG.md

Bug Fixes

WiFi TX Power UI: Fixed visibility issue - TX Power selector now visible in both AP and Client modes (was hidden in AP mode)

Code Quality

cppcheck Static Analysis: Additional cleanup pass
- Replaced C-style casts with static_cast/reinterpret_cast
- Added explicit to single-argument constructors
- Fixed shadow variables and improved const correctness
- Removed unused legacy functions

Dependency Updates

TaskScheduler: 4.0.1 → 4.0.3
ESPAsyncWebServer: 3.8.1 → 3.9.1
AsyncTCP: 3.4.8 → 3.4.9

v2.18.7 (Coredump to Flash - Crash Analysis) 🟢 COMPLETED

Core Dump System

ESP-IDF Coredump to Flash: Automatic crash backtrace capture and storage
- Flash Storage: Crash data saved to dedicated 64KB coredump partition
- Post-Mortem Analysis: Captures Program Counter, task name, exception cause/address, and backtrace (up to 16 addresses)
- Automatic Capture: Triggers on PANIC, TASK_WDT, INT_WDT crashes
- SDK Configuration: Enabled CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH and CONFIG_ESP_COREDUMP_DATA_FORMAT_ELF for all environments
- Auto-Clear: Coredump erased after successful read to prevent re-processing

Crash Log Enhancements

Extended Crash History: JSON format now includes panic details and firmware version
- Exception Info: Program Counter (PC), Task name, Exception Cause, Exception Address
- Firmware Version: Stores version at crash time (not current version) via RTC variables
- Backtrace: Array of memory addresses for addr2line debugging
- Backward Compatible: Old crash entries without panic data continue to work
Web Interface Improvements:
- New "Details" Column: Shows PC address and task name for panic crashes
- Expandable Rows: Click on crash entry to view full exception details with firmware version
- Backtrace Display: Formatted memory addresses (4 per line for mobile readability)
- Copy Buttons:
  - "Copy Exception" - copies complete exception details (version, PC, task, cause, backtrace) as text for reports/issues
  - "Copy addr2line" - copies ready-to-use addr2line command for terminal execution
- Exception Decoder: Human-readable descriptions for common ESP32 exception causes (LoadProhibited, StoreProhibited, etc.)
- Mobile Responsive: Hides "Min Heap" column on mobile, compact backtrace layout

Debug Tools

Test Crash Endpoint: /test_crash triggers intentional null pointer crash for testing
- Demonstrates coredump capture workflow
- Provides 2-second warning before crash
- Useful for verifying crash analysis pipeline

Technical Implementation

crashlog.cpp:
- Added esp_core_dump_get_summary() integration for backtrace capture
- Added RTC variable g_last_version[16] to store firmware version at crash time
- Updated crashlog_update_variables() to save current version to RTC memory
web_api.cpp: Added handleTestCrash() endpoint for testing
crash-log.js: Complete rewrite with expandable rows, exception text export, and copy functionality
index.html: Updated table structure with new Details column
style.css: Added panic details styling and mobile optimizations

Documentation

Release Requirements: Added note to TODO.md - releases must include both firmware.bin (for flashing) and firmware.elf (for crash debugging with addr2line)

Code Quality Improvements

cppcheck Static Analysis Cleanup: Fixed ~40 style warnings across codebase
- Added explicit to single-argument constructors to prevent implicit conversions
- Replaced C-style casts with static_cast/reinterpret_cast for type safety
- Fixed shadow variables and improved const correctness
- Removed 7 unused legacy functions (logging_get_config, webserver_cleanup, checkWiFiTimeout, getWebServer, wifiStop, wifiGetState, crashlog_format_uptime)
- Fixed dead code bug in WiFi scan failure recovery (scanFailureCount reset before check)

Dependency Updates

TaskScheduler: Updated to v4.0.1 (from v3.8.5)

Bug Fixes

WiFi Timeout in Permanent Mode: Fixed 20-minute reboot bug caused by isTemporaryNetwork flag being overwritten in web_interface.cpp
Uptime Display: Enabled formatted uptime display (shows "4m 47s", "2h 15m" instead of raw seconds)

Known Issues

Coredump functionality requires specific SDK configuration which may conflict with certain Arduino framework versions
addr2line analysis requires exact firmware.elf file matching the crashed firmware

v2.18.6 (XIAO ESP32-S3 Support) 🟡 IN DEVELOPMENT

Platform Support

XIAO ESP32-S3 Board Support: Initial implementation
- Pin Mapping: Custom GPIO mapping for XIAO compact pinout
  - Device 1 (UART Bridge): GPIO4/5 (D3/D4 pins)
  - Device 2 (UART2/USB): GPIO8/9 (D8/D9 pins)
  - Device 3 (UART3): GPIO43/44 (D6/D7 pins)
  - RTS/CTS flow control: GPIO1/2 (D0/D1 pins)
- LED Support: Single-color LED on GPIO21 with inverted logic (LOW=ON)
  - Blink-only mode (no RGB colors)
  - FastLED replaced with simple GPIO control for XIAO
- Build Configuration: Added xiao_production and xiao_debug environments
- Web Interface: Board type detection and D-pin display in device configuration
- Testing Status: Basic mode tested (Device1 UART Bridge + Device2 USB with flight controller)

Code Changes

Updated defines.h with XIAO-specific pin definitions and comments
Updated leds.cpp with conditional compilation for single-color LED support
Updated web_api.cpp with XIAO board type detection
Updated device-config.js with GPIO to D-pin mapping table for web interface
Updated status-updates.js with XIAO board name display

Documentation

Updated README.md with XIAO board information and D-pin connections
Updated help.html with XIAO pin mapping table and LED indicators
Updated version to 2.18.6

v2.18.5 (SBUS Phase 3 - Unified Senders + UDP Batching) ✅ COMPLETED

SBUS Phase 3 Implementation ✅

Unified Sender Architecture: Single sendDirect() method for all protocols
- Fast Path: SBUS/Raw protocols use sendDirect() directly (no queue, minimal latency)
- Slow Path: MAVLink/Logs use sendDirect() internally from processSendQueue()
- No Code Duplication: Single transmission point, unified statistics
UDP Batching for SBUS: Optimized network efficiency
- 3-Frame Batching: Combines 3 SBUS frames (75 bytes) into single UDP packet
- Packet Reduction: ~178 → ~25 UDP packets/sec (85% reduction)
- Stale Protection: 50ms timeout for incomplete batches
- Web Statistics: Real-time batching metrics (avg/max frames per batch, efficiency)
Device4 SBUS UDP Support: Full bidirectional SBUS over WiFi
- D4_SBUS_UDP_TX (role 3): Send SBUS frames over UDP with batching
- D4_SBUS_UDP_RX (role 4): Receive SBUS frames from UDP with failover support
- Web UI: IP/Port configuration for both TX/RX modes
- Timing Keeper: Frame repeat for RX mode to smooth WiFi jitter
Protocol Pipeline Optimization: Improved fast/slow path separation
- Smart Queue Processing: processSendQueue() skipped for SBUS roles
- Conflict Resolution: Fixed atomicBatchPackets race condition
- Unified Flush: Single flushBatch() function for all protocols

UI Improvements

Device 4 Network Configuration visibility for SBUS roles
IP validation for TX roles, disabled for RX role
SBUS WiFi Timing Keeper visibility for UDP RX mode
Anti-flap log rate limiting (5sec) to reduce startup spam

Bug Fixes

Fixed UDP transport initialization for D4_SBUS_UDP_RX
Fixed batching statistics calculation (efficiency display)
Fixed web form validation for SBUS UDP roles
Fixed SBUS Timing Keeper logic: save lastValidFrame only from UDP source (not from active source)
Fixed SBUS Timing Keeper visibility: show only for D4_SBUS_UDP_RX (not for UART SBUS outputs)
Optimized tSbusRouterTick task: enabled only for D4_SBUS_UDP_RX (reduced CPU usage for UART-only configs)
Fixed RAW protocol over UDP regression: Removed incorrect "single input" restriction that blocked bidirectional data flow
Fixed buffer allocation bug: Removed D1_SBUS_IN from getOptimalBufferSize() enum check that caused Device4 Network Bridge to use 256 bytes instead of 4096
Fixed USB Host regression: Added out_transfer_busy flag to prevent ESP_ERR_NOT_FINISHED errors caused by Sender task writing data faster than USB transfers complete
Various stability improvements

v2.18.4 (SBUS Phase 2 Complete - Singleton Router + Failsafe) ✅ COMPLETED

SBUS Phase 2 Implementation ✅ COMPLETED

Singleton Router Architecture: Refactored from multiple routers to single global SbusRouter instance
- Smart Source Selection: Automatic source switching based on quality metrics (0-100%)
- Priority System: Device1 (priority 0) > Device2 (priority 1) > UDP (priority 2)
- Anti-Flapping: 500ms delay prevents rapid source switching during signal degradation
- Mode Control: Auto mode (automatic failover) and Manual mode (forced source selection)
Failsafe State Machine: Full three-state failsafe implementation
- OK State: Valid frames received, normal operation
- HOLD State: Signal lost, holds last valid frame for 1 second
- FAILSAFE State: Extended signal loss, outputs failsafe frame (all channels centered)
- Recovery: Automatic return to OK state when valid frames resume
WiFi Timing Keeper: UDP source stability enhancement
- 20ms Frame Repeat: Smooths WiFi jitter for UDP SBUS source only
- TaskScheduler Integration: Periodic tick() execution via tSbusRouterTick task
- Configurable: Controlled via config.sbusTimingKeeper flag
- Memory Efficient: Minimal overhead, reuses last valid frame
Web API Extensions: Full router control and monitoring
- GET /sbus/status: Returns quality, priority, mode, state for all sources
- GET /sbus/set_source: Manual source selection (0=Device1, 1=Device2, 2=UDP)
- GET /sbus/set_mode: Mode control (0=Auto, 1=Manual)
- Removed Legacy: Cleaned up old multi-router helper functions
Code Cleanup & Optimization: Production-ready SBUS implementation
- Removed Dead Code: Eliminated unused variables (lastOutputTime, manualMode, forcedSource)
- Removed Legacy Enums: Cleaned up SbusRouterMode and other unused types
- Removed from SourceState: Deleted lastFrame[25] array (saved 75 bytes per source)
- Removed from SbusFastParser: Deleted static s_lastValidFrame, s_hasValidFrame, lastProcessTime
- Enhanced Logging: Added sourceSwitches counter to source switch log messages
- Architectural Clarity: Timing Keeper only for UDP confirmed as intentional design

Protocol Isolation Fixes ✅ COMPLETED

UDP Protocol Detection: Fixed UDP callback to check protocol optimization mode
- SBUS Mode: Filters packets for valid SBUS frames (25/50 bytes, 0x0F header)
- RAW/MAVLink Mode: Accepts all UDP packets without filtering
- Previous Bug: All UDP packets were SBUS-filtered regardless of protocol mode
- Impact: Now supports RAW and MAVLink protocols over UDP correctly

Web Interface Improvements ✅ COMPLETED

UI Refactoring and Optimization: Reorganized interface structure for better usability
- Advanced Configuration Block: Consolidated Device 4, Protocol, UART, USB, Logging into single collapsible section
- Block Reordering: Optimized layout - SBUS Source Selection first, then Logs, System Status, Crash History, Protocol Stats
- Dynamic Visibility: UART/USB blocks show/hide based on device roles selection
- Visual Improvements: Added icons to all configuration sections, removed redundant information
- Statistics Enhancements: Added color coding for success rates, UDP Batching statistics in compact format
- System Status: Made collapsible with state persistence
Phase 1 Improvements: Collapsible blocks, dynamic labels, SBUS output device fixes, copy button positioning

v2.18.3 (ESP32-S3 Super Mini Support + SBUS Fast Path + Memory Optimization) 🟡 READY FOR TESTING

Release Summary

This release adds ESP32-S3 Super Mini hardware support, implements lightweight SBUS Fast Path architecture, and delivers significant memory optimizations. The codebase is feature-complete but requires hardware testing.

Key Features:

ESP32-S3 Super Mini board support with adaptive LED control
SBUS Fast Path architecture with 10x performance improvement and 15KB → 2KB memory reduction
Memory optimization through intelligent buffer sizing and PSRAM utilization
Enhanced diagnostics with comprehensive PSRAM reporting
SBUS WiFi Timing Keeper for wireless stability

Memory Improvements:

Protocol-aware buffer optimization for different device configurations
PSRAM utilization for non-critical operations
Large JSON document optimization for web operations
Web interface memory optimization plan fully implemented (Stages A-E)
Eliminated String concatenation in hot paths for reduced heap fragmentation

Platform Support - ESP32-S3 Super Mini ✅ IMPLEMENTED (Not Fully Tested)

Multi-Board Architecture: Added support for ESP32-S3 Super Mini with conditional compilation
- LED Pin Adaptation: GPIO48 (WS2815) for Super Mini vs GPIO21 (WS2812) for S3-Zero
- Build Environments: Added supermini_production and supermini_debug configurations
- Board Detection: Runtime board identification via boardType and usbHostSupported fields
- USB Host Limitation: Super Mini lacks USB Host hardware support
Web Interface Adaptation: Dynamic USB mode control based on board capabilities
- Smart UI: USB Host option automatically disabled on Super Mini boards
- Visual Indication: "Host (Not supported on this board)" label for blocked options
- Server Protection: Backend validation prevents USB Host mode selection on Super Mini
- Graceful Fallback: Automatic Device mode selection with warning logging
Hardware Compatibility Notes:
- UART Inversion: Hardware UART inversion support untested on Super Mini
- SBUS Compatibility: May require software-based signal inversion if hardware inversion fails
- Pin Compatibility: All UART pins (4/5, 8/9, 11/12) remain identical between boards
- LED Protocol: WS2815 (Super Mini) is compatible with WS2812 control protocol

Performance Optimization - LED Task Management ✅ COMPLETED

Dynamic LED Task Control: Implemented intelligent enable/disable of LED monitoring task
- Task Export: Made tLedMonitor globally accessible via scheduler_tasks.h
- WiFi State Integration: Automatic task management based on WiFi connection state
- Performance Gain: ~50 iterations/second improvement in stable WiFi modes
LED Task Disable Conditions (saves CPU cycles):
- WiFi Client successfully connected (stable connection)
- WiFi AP mode active (no animation needed)
- Result: ~950+ iterations/second in stable modes
LED Task Enable Conditions (animation required):
- WiFi searching for network (visual feedback)
- WiFi authentication errors (error indication)
- WiFi reconnection attempts (activity indication)
- Initial WiFi client startup (scanning feedback)

Build Configuration

Production Build: pio run -e supermini_production
Debug Build: pio run -e supermini_debug
Original S3-Zero: pio run -e production or pio run -e debug (unchanged)

SBUS Fast Path Architecture ✅ COMPLETED

Fast Path Processing: Lightweight SBUS frame processing with 10x performance improvement
- Virtual Method Integration: Added tryFastProcess() to protocol parser base class
- Direct Output Routing: SBUS frames bypass packet system for immediate forwarding
- Memory Optimization: Reduced from 15KB RAM usage to ~2KB with minimal DMA buffers
- Frame Validation: Built-in resync mechanism for corrupted frame recovery
- Source Tracking: Multi-source support with LOCAL/UART/UDP identification
Device1 SBUS_IN Role: First non-UART bridge role for Device1
- UART1 Reconfiguration: Automatic setup for 100000 8E2 inverted mode
- Smart Router Integration: Device1 input directly feeds SBUS output devices
- Context-Dependent Device4: Adaptive roles (D4_SBUS_UDP_TX/RX) based on configuration
- Hardware Validation: Prevents invalid combinations and provides user feedback
SBUS WiFi Timing Keeper: Maintains wireless SBUS frame timing
- Static Frame Storage: Preserves last valid SBUS frame for retransmission
- 20ms Interval Timing: Ensures consistent frame delivery over WiFi
- Conditional Operation: Only active when timing keeper enabled and SBUS_OUT configured
- Memory Efficient: Uses static class members instead of complex pipeline integration

Memory Optimization & Performance Improvements ✅ COMPLETED

Buffer Size Optimization: Dynamic buffer allocation based on device role and protocol
- SBUS Buffer Optimization: Reduced SBUS device buffers for more efficient memory usage
- UDP SBUS Optimization: Smaller buffers for UDP+SBUS configurations
- Intelligent Sizing Function: getOptimalBufferSize() calculates appropriate buffer sizes
- Protocol-Aware Allocation: Buffer sizes now consider protocol type and device role
PSRAM Memory Management: Enhanced memory allocation with PSRAM support
- Log Buffer PSRAM: Non-critical log buffer moved to PSRAM when available
- Automatic Fallback: Graceful fallback to internal RAM when PSRAM unavailable
- Memory Type Reporting: Diagnostic logging shows PSRAM vs internal RAM usage
- Performance Preserved: DMA-critical buffers remain in fast internal RAM
JSON Document Optimization: Large web interface JSON documents optimized for PSRAM
- Web API Optimization: Config, logs, and status endpoints use PSRAM-aware allocation
- ArduinoJson v7 Integration: Leverages ESP32 heap allocator for automatic PSRAM usage
- Memory Pressure Relief: Temporary memory optimization during web operations
- Transparent Operation: No API changes, automatic memory management
System Diagnostics Enhancement: Extended memory reporting with PSRAM information
- PSRAM Status Reporting: All diagnostic functions now show PSRAM usage (total/free)
- Comprehensive Memory View: Internal RAM + PSRAM status in all system reports
- Memory Optimization Tracking: Monitor memory usage improvements across optimizations
Web Interface Memory Optimization (Stages A-E): Complete memory optimization plan implementation
- Stage A - Streaming JSON Responses: Eliminated large String allocations in /status and /logs endpoints
  - AsyncResponseStream for direct JSON serialization without intermediate buffers
  - Connection: close headers for immediate TCP resource release
  - Refactored with populateConfigJson() helper to avoid code duplication
- Stage B - Collapsible Sections: Reduced unnecessary network requests with smart UI
  - Persistent collapsed state via localStorage (collapse:logs, collapse:protocolStats, collapse:crash)
  - Visible-only polling: /logs only requested when section is expanded
  - Unified toggle utilities: Utils.rememberedToggle() and Utils.restoreToggle()
- Stage C - Static Asset Caching: Immutable cache with automatic versioning
  - Cache-Control: public, max-age=31536000, immutable for all static resources
  - Auto-versioning with 8-char hash (?v=XXXXXXXX) in embed_html.py
  - Cache invalidation on any source file change
- Stage D - PSRAM Config Operations: Eliminated DRAM spikes during import/export
  - Import uses PSRAM buffer (32KB limit) without fallback to DRAM
  - Export streams directly via config_to_json_stream(Print&)
  - ImportData structure for clean PSRAM buffer handoff
  - HTTP 413 response for oversized configs
- Stage E - LWIP/IPv6 Tuning: Reduced TCP memory footprint
  - IPv6 disabled (CONFIG_LWIP_IPV6=n) with related counters zeroed
  - TCP limits reduced: MAX_SOCKETS=8, MAX_ACTIVE_TCP=8, MAX_LISTENING_TCP=4
  - TCP buffers optimized: SND_BUF=2920, WND=2920, RECVMBOX=16
  - UDP settings preserved for AsyncUDP operation
String Operation Optimization: Eliminated all String concatenations in hot paths
- Critical Path Optimizations (executed frequently):
  - handleStatus(): uartConfig and lastActivity now use snprintf with char buffers
  - WiFi disconnect: Removed unused String variable
  - Device initialization: Direct log_msg formatting instead of String building
  - UDP statistics: char buffer for percentage formatting
- Additional Optimizations:
  - crashlog_format_uptime(): Replaced String concatenation with snprintf
  - WiFi hostname generation: Removed unnecessary String() wrapper
  - Config export: Filename generation via snprintf instead of String concatenation
- Impact: Reduced heap fragmentation, predictable memory usage, faster execution

Testing Status & Pending Tasks 🟡

Super Mini Implementation: Code changes completed but not tested on actual hardware
UART Inversion: Hardware inversion functionality unverified on Super Mini platform
LED Functionality: GPIO48 LED control implementation needs physical validation
SBUS Operation: Protocol operation with potential software inversion requirement untested
SBUS Fast Path Testing: Frame processing and timing keeper functionality need field validation
Memory Optimization Validation: Buffer optimizations need stress testing with high data rates
Documentation Update: README.md and web interface help pages not yet updated for Super Mini support

v2.18.2 (Code Refactoring & WiFi TX Power Control) ✅ COMPLETED

Code Organization & Memory Optimization ✅ COMPLETED

Constants Refactoring: Moved domain-specific constants from defines.h to appropriate headers
- WiFi Constants: RSSI thresholds relocated to wifi_manager.h
- LED Constants: Timing and color definitions moved to leds.h
- SBUS Constants: Protocol definitions moved to sbus_common.h
- Crash Log Constants: File size limits moved to crashlog.h
- Web API Constants: HTTP response constants moved to web_api.h
Memory Leak Fix: Resolved Logger flow incorrectly processed in telemetry pipeline
- Root Cause: Logger flow was processed as telemetry data causing frequent ParsedPacket allocations
- Pipeline Fix: Modified processTelemetryFlow() to exclude flows with SOURCE_LOGS
- Performance: Reduced memory leak from ~6 bytes/sec to ~1-2 bytes/sec
- Architecture: Logger flow now processed separately from telemetry pipeline
Memory Optimization: Improved String handling in diagnostics system
- String Operations: Replaced String concatenation with char[] buffers in runAllStacksDiagnostics()
- Diagnostic Logging: Optimized runBridgeActivityLog() to eliminate temporary String objects
- Performance: Reduced potential heap fragmentation from periodic diagnostic tasks

WiFi TX Power Configuration ✅ COMPLETED

Web Interface Control: Added WiFi transmission power setting in web configuration
- Power Range: 6 preset levels from Minimum (2dBm) to Maximum (20dBm)
- Real-time Config: Immediate power adjustment without restart required
- Persistent Storage: WiFi TX power setting saved to configuration file
- ESP32 Integration: Uses esp_wifi_set_max_tx_power() API with 0.25dBm precision
Code Style Improvements: Fixed constructor initialization list formatting consistency
- Comma Placement: Standardized trailing comma style in UartDMA constructor
- Code Consistency: Aligned with project coding standards

v2.18.1 (SBUS Advanced Features & Transport Support) ✅ COMPLETED

Enhanced SBUS Hub Architecture ✅ COMPLETED

Improved Statistics Tracking: Advanced frame categorization and monitoring
- Real vs Generated Frames: Distinction between frames with new data vs timing-maintenance frames
- Unchanged Frame Detection: Channel hash-based detection of unchanged stick positions
- Failsafe Statistics: Dedicated failsafe event counter and state tracking
- Timing Diagnostics: Window-miss detection for transmission timing analysis
- Fresh Data Flag: hadNewDataSinceLastSend flag for precise frame categorization
Optimized Frame Generation: Enhanced timing and efficiency improvements
- Standard SBUS Timing: Corrected to 14ms intervals (71 FPS) for protocol compliance
- Continuous Generation: Always-active frame generation for consistent receiver compatibility
- Improved Failsafe: Better signal restoration detection and flag management
- Smart Routing: Enhanced SBUS input routing logic for complex device configurations

SBUS Transport Support ✅ COMPLETED

UART→SBUS Bridge: Transport SBUS frames over regular UART connections
- UartSbusParser: Dedicated parser for SBUS frames received via UART
- Bridge Flows: UART2→Device3_SBUS_OUT and UART3→Device2_SBUS_OUT configurations
- Frame Validation: Robust start/end byte validation for UART-transported SBUS data
- Use Case: Enable SBUS over any baudrate UART connection between ESP32 devices
UDP→SBUS Bridge: Wireless SBUS transmission over WiFi networks
- UdpSbusParser: Specialized parser for SBUS frames in UDP packets
- Network Bridge: Device4 Network Bridge integration for wireless SBUS transport
- Atomic Packet Handling: Proper UDP packet atomicity with full-buffer clearing on errors
- WiFi SBUS: Real-time RC control over WiFi with <50ms latency targeting

SBUS Routing Enhancements ✅ COMPLETED

UDP Transport Integration: Full UDP routing support for SBUS data streams
- Routing Activation: Enabled Device4 UDP routing in SBUS input calculations
- Transport Statistics: UDP sender SBUS frame counting and diagnostic logging
- Network Compatibility: SBUS frames transmitted as raw 25-byte UDP payloads
SBUS Input Validation: Comprehensive input source validation
- Source Identification: Named detection of Physical SBUS, UART bridges, and UDP inputs
- Conflict Prevention: Single-source enforcement with detailed conflict reporting
- Input Validation: Framework ensures proper SBUS configuration

Diagnostic & Monitoring Improvements ✅ COMPLETED

Enhanced Logging: Comprehensive diagnostic output for SBUS operations
- UART1 Diagnostics: SBUS frame transmission logging for protocol analysis
- UDP Diagnostics: Network-based SBUS frame transmission monitoring
- Parser Statistics: Frame reception counting with invalid frame tracking
- Temporary Diagnostics: Clearly marked diagnostic code for future cleanup

Bug Fixes & Critical Improvements ✅ COMPLETED

Parser Conflict Resolution: Fixed critical data loss in SBUS configurations
- Problem: RawParser/MavlinkParser conflicted with SBUS parsers causing 28% data loss
- Solution: Added hasSbusDevice detection to disable generic flows when SBUS is active
- Impact: Reduced SBUS data loss from 28% to ~0%
- Affected Flows: UDP_Input, UART2_Input, UART3_Input now properly disabled with SBUS

Transport Method Coverage ✅ COMPLETED

Physical SBUS: Direct Device2/3 SBUS_IN → SBUS_OUT connections
UART Transport: SBUS over regular UART at any baudrate (115200-921600+)
WiFi/UDP Transport: Wireless SBUS over local networks with real-time performance
Hybrid Configurations: Multiple simultaneous transport methods with conflict detection

v2.18.0 (SBUS Protocol Implementation & Hub Architecture) ✅ COMPLETED

SBUS Protocol Full Implementation ✅ COMPLETED

SBUS Parser: Complete SBUS frame parsing with validation and statistics
- Frame Validation: Start byte (0x0F) and end byte validation (0x00, 0x04, 0x14, 0x24)
- Channel Extraction: 16-channel data unpacking from 22 bytes using unpackSbusChannels()
- Flags Processing: Frame lost and failsafe flag extraction from SBUS frames
- Statistics: Valid/invalid frame counters, frame lost/failsafe tracking
- Implementation: SbusParser class inheriting from ProtocolParser

Hub Architecture Introduction ✅ COMPLETED

SbusHub Implementation: State-based packet processing replacing queue-based approach
- Problem Solved: Eliminated 99% packet drops caused by queue overflow at 71 FPS
- State Storage: Channel state (16 channels + flags) instead of packet queue
- Timer-based Output: Fixed 14ms interval generation (71.43 FPS) independent of input
- Failsafe Logic: Automatic failsafe activation after 100ms without input data
- Memory Efficiency: No packet queuing, immediate state update and packet release

Protocol Pipeline Integration ✅ COMPLETED

Flow Configuration: Automatic SBUS flow setup for Device2/Device3 roles
- SBUS Input Flow: SBUS_IN devices (D2_SBUS_IN, D3_SBUS_IN) → UART1 routing
- SBUS Output Flow: UART1 → SBUS_OUT devices (D2_SBUS_OUT, D3_SBUS_OUT) routing
- Dynamic Routing: Smart routing calculation based on device role combinations
- Parser Integration: SbusParser automatically instantiated for SBUS input flows

Auto-Protocol Detection ✅ COMPLETED

Startup Detection: Automatic protocol optimization based on device roles
- SBUS Detection: Auto-set protocolOptimization = PROTOCOL_SBUS when SBUS devices present
- Runtime Application: Applied at system startup after config loading
- Statistics Integration: Proper SBUS statistics display in web interface
- Backward Compatibility: No manual protocol selection required

Device Statistics Integration ✅ COMPLETED

TX Statistics: Proper Device2/Device3 TX byte counting for SBUS output
- Hub Integration: SbusHub updates g_deviceStats.device3.txBytes directly
- Device Awareness: Hub knows its device index (IDX_DEVICE3, IDX_DEVICE2_UART2)
- Real-time Tracking: Statistics update with each 25-byte SBUS frame sent
- Web Display: Correct TX statistics in /status interface

SBUS Web Interface ✅ COMPLETED

Statistics Display: Dedicated SBUS statistics rendering in web interface
- Frame Statistics: Valid/invalid frame counts with success rate calculation
- Signal Quality: Frame lost and failsafe counters with percentage rates
- Parser Detection: Improved parser search across all flows (not just first)
- Hub Statistics: Frames received/generated counters from SbusHub

Technical Improvements ✅ COMPLETED

Code Cleanup: Removed obsolete SbusSender class and unused includes
Comment Standards: All code comments converted to English per coding standards
Memory Management: Efficient packet handling without memory leaks
Error Handling: Robust frame validation with graceful error recovery

v2.17.0 (MAVLink Parser Channel Fix & Performance Optimizations) ✅ COMPLETED

Critical MAVLink Parser Channel Fix ✅ COMPLETED

Channel Conflict Resolution: Fixed critical bug where all MAVLink parsers shared the same channel causing state conflicts
- Root Cause: All 5 MAVLink parsers used rxChannel=0, causing shared rxStatus state corruption between flows
- Solution: Assign unique channels (0-4) to each parser: Telemetry(0), USB(1), UDP(2), UART2(3), UART3(4)
- Result: Eliminated MAVLink sequence gaps and fixed MAVFtp packet loss during parameter download
- Implementation: Modified MavlinkParser constructor to accept channel parameter, updated all instantiations

Bidirectional Pipeline Implementation ✅ COMPLETED

Architecture Implementation: Partial implementation of bidirectional pipeline design (Aug 30 plan)
- Input Buffers: Added 4 separate input buffers for USB/UDP/UART2/UART3 sources
- Anti-echo Protection: Implemented packet source tracking to prevent loops
- Physical Interface Tracking: Added interface identification for routing decisions

Pipeline Performance Optimizations ✅ COMPLETED

Non-blocking Senders: Removed blocking timeouts from USB and UDP senders (Sep 1)
- Issue: Senders blocked main loop waiting for batch timeouts, reducing iterations from 1000 to 780-850/sec
- Fix: Exit immediately if conditions not met, check on next iteration instead of waiting
Input Flow Time Limits: Added temporal constraints for bidirectional processing (Sep 1)
- Issue: processInputFlows() had no time limits, blocking main loop during FTP transfers
- Fix: Added 5ms time limit and iteration caps to prevent main loop stalls
Sender Task Implementation: Moved heavy USB operations to dedicated task (Sep 1)
- Architecture: Separate task for USB bulk transfers to prevent main loop blocking
- Queue Management: Ring buffer for packet passing between main loop and sender task

UART Batch Processing Improvements ✅ COMPLETED

Batch Read Implementation: Optimized UART1 data reading for higher throughput (Sep 1)
- Method: Read up to 320 bytes per batch instead of single bytes
- Buffer Management: Improved circular buffer write patterns for batch operations
- Statistics: Enhanced throughput monitoring for batch vs single-byte performance

Telemetry Flow Architecture Refinements ✅ COMPLETED

Flow Prioritization: Separated telemetry and input flow processing (Sep 2)
- Telemetry Priority: Higher priority for FC→GCS direction with exhaustive parsing
- Input Flow Limits: Time-bounded processing for GCS→FC direction to prevent blocking
- Buffer Balance: Optimized buffer allocation between bidirectional flows

v2.16.0 (MAVLink Routing Implementation & Input Gateway) ✅ COMPLETED

MAVLink Routing Architecture Implementation ✅ COMPLETED

Parser-Router Separation: Moved target extraction from router to parser for clean architecture
- MavlinkParser: Added extractTargetSystem() and extractTargetComponent() methods using official pymavlink getters
- MAVLink Getters: Implemented proper target extraction using mavlink_msg_*_get_target_system() functions
- Routing Flag: Added routingEnabled flag to enable target extraction only when routing is active
- Code Quality: Replaced magic numbers (20, 21, 23...) with MAVLink constants (MAVLINK_MSG_ID_PARAM_REQUEST_READ, etc.)
Router Simplification: Removed duplicate target extraction logic from MavlinkRouter
- Deleted Methods: extractTargetSystem() and isRoutableMessage() - now handled by parser
- Broadcast Fix: Corrected invalid broadcast check - sysid=255 is GCS, not broadcast target
- ROUTABLE_MSG_IDS: Removed unused message ID array after parser refactoring

Input Gateway Implementation for Device2-4 to UART1 ✅ COMPLETED

Device Input Routing: Created InputGateway class for routing device2-4 data to UART1
- Temporary Passthrough: Direct data forwarding to uartBridgeSerial before full bidirectional pipeline
- MAVLink Learning: Extracts sysid from incoming MAVLink packets for address book population
- Interface Mapping: Maps device interfaces to router address book for future routing
Protocol Integration: Connected input gateway to protocol pipeline
- Router Learning: learnAddress() method for manual address book updates from input gateway
- Statistics Tracking: Counters for processed packets and learned sysids
- Configuration: Enabled only when MAVLink routing is active in config

Code Quality & Magic Numbers Elimination ✅ COMPLETED

MAVLink Constants: Replaced all magic numbers with proper MAVLink constants
- Router Arrays: ALWAYS_BROADCAST_IDS now uses MAVLINK_MSG_ID_HEARTBEAT, MAVLINK_MSG_ID_SYS_STATUS, etc.
- Parser Methods: Switch cases use MAVLINK_MSG_ID_PARAM_REQUEST_READ instead of 20, etc.
- Input Gateway: Added TODO comments for future magic number replacement (0xFD, 0xFE, offsets)
Diagnostic Logging: Added comprehensive debugging for routing development
- Router Dumps: Periodic address book dumps every 5 seconds with routing statistics
- Parser Target Logs: Extraction logging for routable messages with throttling
- Pipeline Flags: Routing enabled/disabled status logging during initialization

Bug Fixes & Critical Corrections ✅ COMPLETED

Broadcast Target Fix: Removed incorrect targetSys == 255 broadcast check in router
- Root Cause: sysid=255 is standard GCS identifier, not broadcast indicator
- Impact: Fixed routing hits calculation - commands to/from GCS now route correctly
- Address Book: GCS entries (sysid=255) now properly used for unicast routing
Architecture Consistency: Fixed parser/router responsibility separation
- File Structure: Created mavlink_parser.cpp for method implementations (was inline in header)
- Method Declarations: Proper header/implementation separation to avoid compilation conflicts

v2.15.7 (LED System Refactoring & Optimization) ✅ COMPLETED

LED System Complete Refactoring ✅ COMPLETED

Code Size Reduction: leds.cpp reduced from 600 to 462 lines (-138 lines, 23% reduction)
Architecture Unification: Replaced 6 separate blinking systems with 1 universal system
- Old System: Individual functions for WiFi, Ethernet, UART1-4 LED blinking
- New System: Single BlinkState structure array with BlinkType enum
- State Management: Centralized blinking logic in unified updateLED() function
Data Structure Optimization: Reduced from 40+ individual variables to 5 structured elements
- BlinkState Structure: active, isOn, count, onTime, offTime, colorValue, nextTime
- BlinkType Enum: BLINK_WIFI, BLINK_ETH, BLINK_UART1-4 for type identification
- State Array: blinkStates[6] for all LED types with proper initialization

Performance & Safety Improvements ✅ COMPLETED

Mutex Optimization: Single mutex capture per update cycle instead of multiple captures
Time Handling: Proper millis() overflow handling with safe time arithmetic
Code Cleanup: Removed unused functions and duplicate logic
- Removed: setLED() function (-9 lines)
- Eliminated: Counter update duplication (-6 lines)
Volatile Warning Fix: Replaced deprecated volatile-- with explicit assignment

Code Quality Enhancements ✅ COMPLETED

Maintainability: Easy addition of new blink patterns through enum extension
Readability: Clear separation of state management and LED control logic
Safety: Proper volatile variable handling and thread-safe operations
Efficiency: Optimized update loop with early returns and reduced function calls

WiFi Manager Code Refactoring & Style Improvements ✅ COMPLETED

Code Size Reduction: wifi_manager.cpp reduced from 586 to 538 lines (-48 lines, 8.2% reduction)
Function Naming: Renamed all functions from snake_case to camelCase for consistency
- Old: wifi_manager_init(), wifi_manager_process(), wifi_manager_is_ready_for_data()
- New: wifiInit(), wifiProcess(), wifiIsReady()
- Updated: 8 function declarations + implementations + 8 external call sites
Constants Extraction: Replaced magic numbers with named constants
- WiFi Constants: WIFI_RECONNECT_DELAY_MS, WIFI_TX_POWER_LEVEL, WIFI_MIN_HEAP_BYTES
- Buffer Sizes: WIFI_SSID_MAX_LEN, WIFI_PASSWORD_MAX_LEN, WIFI_CONNECT_TIMEOUT_MS
- Utility: WIFI_MDNS_SERVICE_PORT, WIFI_MAC_SUFFIX_BUFFER_SIZE

Code Quality & Maintainability Improvements ✅ COMPLETED

Error Handling Unification: Created helper functions for consistent error reporting
- ESP-IDF Errors: handleEspError() function replaced 6 duplicate error handling blocks
- mDNS Errors: logMdnsError() function unified mDNS error reporting
- Credentials Helper: setWifiCredentials() function replaced 4 duplicate strncpy operations
Legacy Code Cleanup: Removed unused and historical code elements
- Removed: wifiIsConnected() legacy function (unused, 5 lines saved)
- Cleaned: Historical comments about code migration and architecture changes
- Fixed: Misleading constant name WIFI_TX_POWER_DBM → WIFI_TX_POWER_LEVEL
Variable Naming: Improved variable names for better code readability

Flow Control System Complete Refactoring ✅ COMPLETED

Architecture Simplification: Replaced complex auto-detection system with simple ESP-IDF implementation
- Removed Files: flow_control.cpp and flow_control.h (complex detection logic eliminated)
- Removed Globals: FlowControlStatus structure and global variable from main.cpp
- Simplified Logic: Direct ESP-IDF UART_HW_FLOWCTRL_CTS_RTS usage instead of custom detection
Object-Oriented Flow Control: Integrated flow control status into UART interface
- New Method: getFlowControlStatus() virtual method in UartInterface base class
- UART Implementation: Flow control status reporting through UartDMA class
- Web Integration: Updated web_api.cpp to use UART interface method instead of global function
Hardware Configuration: Flow control enabled only for UART1 with proper GPIO configuration
- GPIO Pins: RTS=GPIO6, CTS=GPIO7 as defined in hardware specification
- Threshold: RX flow control threshold set to 100 bytes (~78% of 128-byte FIFO)
- User Control: Flow control activated only when explicitly enabled via web interface
Build System Fixes: Resolved compilation issues from previous refactoring
- Header Dependencies: Added #include <Arduino.h> to uart_interface.h for String type
- Dead Code Removal: Cleaned up remaining references to globalTxBytesCounter in protocol headers
- Incremental Build: Fixed issues where header-only changes weren't properly recompiled
- Network Detection: foundNow → networkFoundNow
- IP Address: ip_str → ipAddressStr
- WiFi Config: cfg → wifiConfig
Micro-optimizations: Small performance improvements
- Removed: Duplicate extern declarations
- Optimized: Cached hostname length in validation loop

Web Interface Code Optimization & Cleanup ✅ COMPLETED

Code Size Reduction: Combined optimization of web API and interface modules
- web_api.cpp: Minor cleanup with constants for magic numbers and historical comment removal
- web_interface.cpp: Reduced from 211 to 192 lines (-19 lines, 9% reduction)
HTTP Response Optimization: Created helper function for gzipped static file serving
- Before: 7 identical 3-line blocks for CSS/JS files (21 lines total)
- After: Single sendGzippedResponse() helper + 7 one-line calls (13 lines total)
- Eliminated Duplication: Response creation, gzip header, and sending logic unified
Magic Numbers → Named Constants: Improved code readability
- HTTP_PORT (80): Web server port configuration
- UPLOAD_BUFFER_RESERVE (4096): File upload buffer pre-allocation size
- ASCII_PRINTABLE_THRESHOLD (32): Character filtering threshold for uploads
Code Quality Improvements: Removed historical references and unnecessary comments
- Cleaned: Architecture change comments and implementation history notes
- Simplified: Function documentation to focus on current behavior rather than past changes

Task Scheduler Code Cleanup ✅ COMPLETED

Historical Comments Removal: Cleaned up scheduler_tasks.cpp from legacy references
- Removed 10+ comments: All "Statistics update tasks removed" and similar historical notes
- Focused Documentation: Code comments now describe current functionality rather than past architecture changes
- Cleaner Codebase: Eliminated references to removed statistics update tasks and deprecated functionality

v2.15.6 (Types System Refactoring & Code Organization) ✅ COMPLETED

Major Code Architecture Refactoring ✅ COMPLETED

Types.h Modularization: Split large types.h file into logical modules
- File Reduction: types.h reduced from ~400 to ~264 lines for faster compilation
- Logical Separation: Device types, statistics, and core types properly separated
- Better Organization: Clear modular structure by functionality
- Compilation Speed: Changes to device statistics no longer recompile entire project

New Modular Header Structure ✅ COMPLETED

device_stats.h: Device statistics structure and management functions
- DeviceStatistics Structure: Atomic counters for all 4 devices (Device1-4)
- Global Instance: extern DeviceStatistics g_deviceStats declaration
- Management Functions: initDeviceStatistics() and resetDeviceStatistics()
device_stats.cpp: Implementation of statistics functions and global instance
device_types.h: Device roles, enums, and configuration structures
- Device Role Enums: Device1Role, Device2Role, Device3Role, Device4Role
- Core Enums: BridgeWiFiMode, UsbMode, LogLevel (moved from types.h)
- Config Structure: Complete configuration structure with proper enum types
types.h Simplified: Core system types only
- Essential Types: BridgeMode, WiFiClientState, LedMode, SystemState
- BridgeContext: Protocol pipeline context (maintained for compatibility)
- Include Integration: Automatically includes new modular headers

Cross-Core Communication Cleanup ✅ COMPLETED

Removed Inter-Core Hacks: Eliminated unnecessary cross-core synchronization
- Global Pipeline Pointer: Removed g_pipeline global variable
- Memory Barriers: Removed __sync_synchronize() calls
- External Declarations: Cleaned up bridge_processing.h
Legacy Buffer Methods: Removed unused cross-core communication methods
- writeWithSource(): Removed from circular_buffer.h
- readWithSource(): Removed from circular_buffer.h
- writeInternal(): Removed helper method
Architecture Simplification: All components now run on Core 0, no sync needed

Dead Code Elimination ✅ COMPLETED

Statistics Update Functions: Removed empty update functions
- Diagnostics Cleanup: Removed updateMainStats(), updateDevice3Stats(), updateDevice4Stats()
- Scheduler Tasks: Removed unused statistics update tasks from TaskScheduler
- Task References: Cleaned up all enable/disable/addTask calls for removed tasks

Configuration Management Refactoring ✅ COMPLETED

Code Quality Improvements: Enhanced maintainability and reduced duplication in config.cpp
Constants Extraction: Replaced magic numbers with named constants
- Network: DEFAULT_BAUDRATE (115200), DEFAULT_UDP_PORT (14560)
- Processing: JSON_PREVIEW_SIZE (200), IP_BUFFER_SIZE (15)
Helper Functions: Created utility functions to eliminate code duplication
- Migration Helper: finalizeMigration() replaced 7 duplicate log+version blocks (-14 lines)
- Device Defaults: setDeviceDefaults() replaced 2 duplicate device role assignments (-6 lines)
Code Cleanup: Removed historical comments and improved consistency
- Removed: "NEW" markers from UDP batching implementation
- Enhanced: Protocol constant usage (0 → PROTOCOL_NONE for better readability)
Scheduler Task Cleanup: Removed empty if-blocks and historical comments from scheduler_tasks.cpp
- Eliminated: 4 empty Device3/Device4 if-blocks (legacy after refactoring)
- Cleaned: 10+ historical comments about removed statistics functions

Crash Logging System Refactoring ✅ COMPLETED

Code Quality Improvements: Enhanced maintainability and reduced duplication in crashlog.cpp
Helper Functions: Created utility functions to eliminate code duplication
- Empty JSON Structure: createEmptyLog() helper replaced 5 duplicate initialization blocks
- Fallback JSON: getFallbackJson() helper replaced 3 duplicate error return strings
- File Writing: writeJsonToFile() helper replaced 3 duplicate file write operations
Constants: Added CRASHLOG_MAX_FILE_SIZE constant for better code readability
Code Cleanup: Improved consistency and maintainability throughout crash logging system

Legacy Code and Comment Cleanup ✅ COMPLETED

Historical Comments Removal: Cleaned up outdated comments throughout codebase
Files Updated: adaptive_buffer.h, bridge_processing.h, circular_buffer.h, uartbridge.cpp/h
Legacy Code Removal: Removed unused enum DataSource from circular_buffer.h
Comment Consistency: Simplified technical comments while preserving TODO markers and diagnostics

Protocol Pipeline API Cleanup ✅ COMPLETED

Legacy Parameter Removal: Eliminated unused txCounter parameter from all PacketSender constructors
Dead Code Elimination: Removed updateTxCounter() helper functions and globalTxBytesCounter field
API Simplification: Simplified constructor calls by removing nullptr parameters across pipeline
Constants Extraction: Replaced magic numbers with named constants for buffer sizes
- DEFAULT_MAX_PACKETS (20), DEFAULT_MAX_BYTES (8192) for UART/UDP senders
- USB_MAX_PACKETS (128), USB_MAX_BYTES (24576) for USB sender optimized buffers
Code Quality: Improved maintainability and self-documenting code through consistent naming
Project Structure: Moved device_init files to src root
- Simplified Paths: devices/device_init.h → device_init.h
- Include Updates: Fixed all include paths throughout codebase
- Directory Cleanup: Removed empty devices/ directory

Forward Declaration Conflicts Resolution ✅ COMPLETED

Enum Type Conflicts: Fixed forward declaration vs full definition mismatches
- BridgeWiFiMode, UsbMode, LogLevel: Moved complete definitions to device_types.h
- Removed Conflicts: Eliminated forward declarations with base types
- Proper Dependencies: Maintained correct include order through types.h
Include Path Optimization: Updated all files requiring new headers
- main.cpp: Added device_stats.h include, updated initialization
- web_api.cpp: Added device_stats.h include for statistics access
- uartbridge.cpp: Removed duplicate statistics initialization

USB Host Code Style Refactoring ✅ COMPLETED

Class Structure: Created proper usb_host.h header file with class declarations
Method Decomposition: Split large handleDeviceConnection() into focused methods
- openDevice(): Device opening and validation (8 lines)
- getDeviceInfo(): Device information retrieval (17 lines)
- claimInterface(): Interface claiming with error handling (12 lines)
- setupTransfers(): USB transfer setup and initialization (23 lines)
CDC Interface Refactoring: Improved findCDCInterface() method structure
- findBulkEndpoints(): Separated endpoint discovery logic (44 lines)
- Better Error Handling: Early returns instead of deep nesting
- Enhanced Logging: Detailed debug information for USB operations
Naming Consistency: Updated all methods to match project camelCase style
- Task Methods: usb_host_task → usbHostTask
- Callbacks: client_event_callback → clientEventCallback
- Variables: bulk_in_ep → bulk_in_endpoint
Documentation: Added comprehensive method comments and parameter descriptions

Technical Benefits 🚀

Faster Compilation: Modular headers reduce interdependencies
Cleaner Architecture: Clear separation of concerns across modules
Better Maintainability: Smaller focused files easier to understand and modify
Reduced Memory Usage: Eliminated unused tasks, variables, and functions
Improved Code Quality: Consistent style and better error handling throughout
Lock-free Performance: Removed unnecessary synchronization primitives

v2.15.5 (Statistics & LED System Refactoring) ✅ COMPLETED

Major Architecture Refactoring ✅ COMPLETED

Unified Device Statistics: Complete migration to atomic-based statistics system
- Atomic Operations: Replaced critical sections with std::atomic<unsigned long> and memory_order_relaxed
- Global Statistics: Centralized DeviceStatistics g_deviceStats for all 4 devices (Device1-4)
- Thread Safety: Eliminated spinlocks and critical sections for lock-free statistics
- Memory Reduction: Removed task-local counters and UartStats structure
- Simplified Architecture: Direct atomic increments throughout the codebase

Device Statistics Centralization ✅ COMPLETED

DeviceCounter Structure: Standardized RX/TX byte counters for all devices
- Device1: UART1 primary interface statistics
- Device2: USB/UART2 secondary interface statistics
- Device3: UART3 mirror/bridge interface statistics
- Device4: UDP network interface statistics
System-wide Counters: Added global activity tracking and system start time
Web Interface Integration: All statistics accessible via atomic loads
Reset Functionality: Unified statistics reset across all devices

LED Monitor Task Implementation ✅ COMPLETED

Centralized LED Management: Replaced scattered LED calls with unified monitor task
- TaskScheduler Integration: 50ms interval LED monitoring task
- Snapshot Comparison: Efficient LED state updates using LedSnapshot structure
- Activity Detection: Smart LED updates only when device activity changes
- Bridge Mode Awareness: LED task enabled/disabled based on bridge mode
Performance Optimization: Eliminated redundant LED calls throughout codebase
Code Simplification: Removed LED timing variables from bridge processing

Protocol Pipeline Integration ✅ COMPLETED

Sender Statistics Cleanup: Removed static counters from UartSender and UdpSender
- Direct Statistics: Senders now update global g_deviceStats directly
- Memory Optimization: Eliminated duplicate statistics tracking
- Unified Interface: All statistics accessible through single global structure
Pipeline Statistics: Protocol processing statistics integrated with global system

Web Interface Statistics Overhaul ✅ COMPLETED

Atomic Statistics Access: All web API endpoints use atomic loads
- Lock-free Operations: Replaced critical sections with load(std::memory_order_relaxed)
- Real-time Updates: Direct access to current statistics without blocking
- JSON Field Compatibility: Maintained existing field names for frontend compatibility
Statistics Reset: Simplified reset functionality using atomic stores
Diagnostic Integration: Enhanced statistics reporting in web interface

Code Architecture Cleanup ✅ COMPLETED

Legacy Statistics Removal: Eliminated UartStats structure and related functions
- Types.h Cleanup: Removed UartStats, statsMux, and old statistics functions
- Bridge Context: Simplified BridgeContext initialization signature
- Function Signatures: Updated all initialization functions to remove UartStats parameters
Critical Section Elimination: Removed all portMUX-based statistics protection
Memory Efficiency: Reduced memory footprint through unified statistics approach

Technical Benefits 🚀

Lock-free Performance: Atomic operations eliminate contention and improve throughput
Simplified Maintenance: Single statistics system across entire codebase
Better Reliability: No deadlocks or race conditions in statistics collection
Reduced Memory Usage: Eliminated duplicate counters and synchronization primitives
Cleaner Architecture: Clear separation between statistics collection and LED management

v2.15.4 (UDP Sender Refactoring & Protocol-Aware Batching) 🚀

Major Architecture Simplification ✅ COMPLETED

SPSC Queue Removal: Eliminated complex inter-core Single Producer Single Consumer queue system
- Removed Components: device4Task completely deleted, UdpTxQueue removed from UdpSender
- Memory Reduction: ~6KB saved (4×1500 byte queue slots + task overhead)
- Latency Improvement: Direct UDP transmission without inter-core queuing delays
- Code Simplification: 300+ lines of complex synchronization code removed

Direct UDP Integration ✅ COMPLETED

Direct AsyncUDP: UdpSender now uses AsyncUDP transport directly (no task intermediary)
UART→UDP Path: processDevice1Input() → CircularBuffer → Pipeline → UdpSender → AsyncUDP (direct)
UDP→UART Path: AsyncUDP onPacket → uartBridgeSerial->write() (direct bypass of Pipeline)
Statistics Integration: UDP TX/RX stats moved to static UdpSender members for thread-safe access
Transport Creation: UDP transport created in main.cpp for both Bridge and Logger modes

Buffer Architecture Separation ✅ COMPLETED

Dual Buffer System: Separate circular buffers for different operational modes
- Telemetry Buffer: For UART→USB/UDP telemetry processing (Bridge mode)
- Log Buffer: For line-based log processing (Logger mode, 1024 bytes)
Memory Optimization: Only allocate needed buffer per mode (Logger saves ~1KB+ adaptive buffer)
Buffer Manager: New buffer_manager.h/cpp for centralized buffer allocation/deallocation
Context Separation: BridgeContext.buffers struct replaces old adaptive.circBuf reference

UDP Logger Mode Enhancements ✅ COMPLETED

Buffer Initialization: UDP log buffer properly zeroed to prevent garbage data transmission
WiFi Connection Checks: Logger task clears buffers when WiFi disconnected
Line Parser Improvements: Enhanced LineBasedParser supports \r\n, \r, \n line endings
Long Line Handling: Graceful handling of lines without endings (skip with warning)
Logger-Bridge Separation: UART telemetry ignored in Logger-only mode (prevents buffer conflicts)

Protocol Pipeline Architecture ✅ COMPLETED

Mode-Specific Initialization: Pipeline uses correct buffer based on Device4 role
- Logger Mode: Uses logBuffer + LineBasedParser
- Bridge Mode: Uses telemetryBuffer + RawParser/MavlinkParser
Buffer Validation: Proper null-pointer checks for buffer availability
Error Handling: Clear error messages for buffer allocation failures

Compilation & Integration Fixes ✅ COMPLETED

Static Variable Definitions: UDP statistics properly defined in udp_sender.cpp
Include Dependencies: Added buffer_manager.h includes to uart/uartbridge.cpp
Context Access: scheduler_tasks.cpp uses getBridgeContext() for buffer access
Bridge Processing: Added Logger mode checks to prevent telemetry buffer usage

Architecture Benefits 🚀

Simplified Design: Removed 3 complex architectural layers (SPSC, Device4Task, injection)
Better Performance: Direct UDP transmission reduces latency and CPU overhead
Memory Efficient: Mode-specific buffer allocation saves memory
Maintainable Code: Cleaner separation between Logger and Bridge functionality
Robust Logging: UDP Logger mode with proper WiFi handling and line parsing

Final Architecture Stabilization ✅ COMPLETED

Fixed Sender Indices: Implemented stable IDX_USB=0, IDX_UART3=1, IDX_UDP=2 sender routing
- Eliminated Array Shifting: Fixed sender indices prevent routing instability
- PacketSource Integration: Added SOURCE_TELEMETRY, SOURCE_LOGS, SOURCE_DEVICE4 packet tagging
- DataFlow Architecture: Multi-stream processing with separate Telemetry and Logger flows
- Sender Mask Routing: Precise packet routing with SENDER_USB, SENDER_UART3, SENDER_UDP masks
Bridge Processing Fix: Resolved USB telemetry blocking in Logger mode
- Logger Mode Issue: USB received no data when Logger was active (bridge_processing.h)
- Root Cause: processDevice1Input() blocked UART→telemetryBuffer in D4_LOG_NETWORK mode
- Solution: Removed blocking condition, USB always processes data through telemetryBuffer
- Result: Logger mode with simultaneous USB telemetry and UDP log transmission
UDP Sender Universal Naming: Renamed MAVLink-specific naming to universal atomic packet handling
- Renamed: mavlink* → atomic* (atomicBatchBuffer, processAtomicPacket, etc.)
- Scope: Universal batching for MAVLink telemetry, line-based logs, and future atomic packets
- Maintained: All existing batching functionality and performance optimizations
- Prepared: Framework for packet-type-specific batching strategies via PacketSource
WiFi Connectivity Universalization: Created unified WiFi readiness checking
- New Function: wifi_manager_is_ready_for_data() works for both AP and Client modes
- AP Mode: Checks for connected clients before allowing data transmission
- Client Mode: Checks connection status to target network
- Integration: Used across UDP Logger, UDP Sender, and other network components
- Legacy: Maintained wifi_manager_is_connected() for compatibility
UDP Batching Configuration Control: Added configurable UDP packet batching for legacy GCS compatibility
- Configuration Field: New udpBatchingEnabled setting (default: enabled) in config version 8
- Web Interface: Added checkbox in Device 4 Network Configuration panel
- Backend Integration: UdpSender.setBatchingEnabled() method for runtime configuration
- Automatic Migration: Existing configurations upgraded to version 8 with batching enabled
- Performance Control: Users can disable batching if GCS doesn't support batched UDP packets
- Logging: Clear indication when UDP batching is enabled/disabled in system logs

Architecture Evolution Within v2.15.3 📈

Phase 1: Initial SPSC queue implementation for Device 4 Pipeline integration
Phase 2: Real-world testing revealed complexity vs benefit imbalance
Phase 3: Architecture simplified - removed SPSC queue, implemented direct UDP + buffer separation
Phase 4: Final stabilization - fixed routing, universal naming, WiFi handling improvements
Result: Production-ready, maintainable, and performance-optimized architecture

v2.15.2 (UDP Sender Refactoring & Protocol-Aware Batching) 🚀

UDP Sender Architecture Overhaul ✅ COMPLETED

Protocol-Aware Batching: Separate MAVLink and RAW packet batching strategies
- MAVLink Packets: Optimized batching with keepWhole integrity (2-5 packets per batch)
- RAW Data: Legacy batching for non-protocol data streams
- Smart Routing: Automatic packet classification using keepWhole flag from parsers
- Adaptive Thresholds: Different limits for normal (2 packets/600 bytes/5ms) vs bulk mode (5 packets/1200 bytes/20ms)

Network Transmission Efficiency ✅ COMPLETED

MTU-Aware Batching: Up to 1400 bytes per UDP datagram for optimal network utilization
Bulk Mode Integration: Extended timeouts (20ms) for MAVFtp transfers, low latency (5ms) for telemetry
Timeout-Based Flushing: Prevents packet stalling during low-traffic periods
Protocol Consistency: Unified approach with USB sender optimizations

Code Architecture Cleanup ✅ COMPLETED

TransmitHints Simplification: Removed deprecated canBatch and urgentFlush flags
Parser Updates: Cleaned up mavlink_parser.h and raw_parser.h hint assignments
Diagnostic Logging: Added UDP-specific debug traces for batch operations and timeout events
Memory Safety: Proper destructor with batch flushing before cleanup

v2.15.1 (Task Priority Optimization & USB Batching Improvements) 🚀

Task Priority Rebalancing ✅ COMPLETED

DMA Task Priority Increase: Elevated DMA task priority above UartBridge task
- Problem Solved: Eliminated UART FIFO overflow issues during high-throughput operations
- Result: Stable data loading without packet loss
- Architecture: Better real-time performance for DMA operations
- Impact: More reliable MAVFtp and bulk transfer operations

USB Batching Timeout Optimization ✅ COMPLETED

Adaptive Batch Timeouts: Different timeouts for normal vs bulk modes
- Normal Mode: 5ms timeout for low latency telemetry
- Bulk Mode: 20ms timeout for optimal MAVFtp batching efficiency
- Smart Fallback: Partial batch transmission on timeout to prevent data stalling
- Buffer Size Unification: TX buffer increased to 2048 bytes across USB Device/Host modes
Complete Partial Write Elimination: Full architectural cleanup
- Removed: Pending buffer structure, flushPending() method
- Simplified: Single packet and batch transmission without partial writes
- Enhanced: Timeout-based partial batch transmission for stuck scenarios

System Stability Improvements ✅ COMPLETED

USB Block Detection Timeout: Increased from 500ms to 1000ms for better detection accuracy
Pool Exhausted Logging: Rate limiting (1/second) and reduced severity (INFO vs WARNING)
Statistics Interface Fix: Real MAVLink statistics instead of hardcoded zeros
- Backend: getSender() methods for accessing real USB transmission counters
- Frontend: Updated web interface with accurate packet counts and error statistics

v2.15.0 (MAVLink Parser Refactoring to Byte-wise Parsing) 🚀

Major MAVLink Parser Simplification

Byte-wise Parsing: Migrated from complex state machine to standard pymavlink byte-wise parsing
- Removed Complexity: Eliminated stash buffer, consume logic, prefix bytes tracking
- Standard Approach: Using mavlink_parse_char() for each byte - industry standard
- Code Reduction: Parser reduced from ~500 to ~300 lines
- No More Deadlocks: Removed PacketAssembler and incomplete packet tracking

BulkModeDetector Implementation

Smart Detection: Decay counter mechanism for MAVFtp and parameter bulk transfers
- Hysteresis: ON at 20 packets/sec, OFF at 5 packets/sec
- 100ms Decay: Counter decrements every 100ms for smooth transitions
- Targeted Detection: Only counts FILE_TRANSFER_PROTOCOL and PARAM messages
- Adaptive Flushing: Immediate flush in bulk mode, batched in normal mode

USB Batching Architecture v2 ✅ COMPLETED

Complete Rewrite: Full USB sender architecture overhaul for data integrity
- Pending Buffer: Added protection against partial write data loss
- Helper Methods: applyBackoff(), resetBackoff(), inBackoff(), updateTxCounter(), commitPackets(), flushPending(), sendSinglePacket()
- 4-Step Algorithm: Linear processing - flush pending → handle partials → single packets → bulk batching
- N/X/T Thresholds: 4 packets OR 448 bytes OR 5ms timeout for batch flushing
- Bulk Mode Transitions: Force flush on bulk mode exit to prevent latency
Memory Pool Enhancement: Increased 128B pool from 20 to 60 blocks for MAVFtp transfers
Queue Architecture: Migrated from std::queue to std::deque for direct indexing and batch planning
Compiler Fixes: Resolved type deduction errors in min() calls with explicit std:: namespace

USB Block Detection & Memory Pool Protection ✅ COMPLETED

Blocked USB Detection: Smart detection when COM port closed on host side
- Timeout-based Logic: 500ms timeout when availableForWrite() value unchanged
- Memory Pool Protection: Auto-clear all queues to prevent pool exhaustion on startup
- Recovery Detection: Keep 1 test packet for automatic unblock detection
- Diagnostic Logging: [USB-DIAG] USB blocked/unblocked messages for debugging
Memory-Safe Operations: Proper packet.free() calls in clearAllQueues()
Startup Protection: No more Pool exhausted for size X, using heap messages when USB dead
Enhanced enqueue(): Override in UsbSender to limit packets during blocked state

MAVLink Statistics Web Interface Fix ✅ COMPLETED

Accurate Statistics Display: Fixed web interface showing zeros for MAVLink stats
- Backend Changes: Added getSender() methods to ProtocolPipeline for sender access
- Real Data Sources: packetsSent/packetsDropped now from actual USB sender statistics
- Proper Error Counting: Detection errors now counted from MAVLINK_FRAMING_BAD_CRC/BAD_SIGNATURE
- Field Renaming: packetsDetected → packetsParsed for clarity
Frontend Updates: Redesigned renderMavlinkStats() with relevant metrics
- Packet Statistics Panel: Parsed, Sent, Dropped, Errors
- Packet Analysis Panel: Average Size, Size Range, Last Activity
- Removed Deprecated: Resync Events, Total Bytes, Transmitted fields
Data Integrity: All statistics now show real values instead of hardcoded zeros

Protocol Pipeline Fix

Critical Logic Fix: Fixed incorrect consume order in protocol_pipeline.h
- Before: Only consumed bytes when packets found (data loss!)
- After: ALWAYS consume bytes first, THEN distribute packets
- Universal Pattern: Works for all parsers (MAVLink, RAW, future SBUS/CRSF)

Cleanup and Maintenance

Priority System Removal: Completely removed packet priority infrastructure
- Deleted: enum PacketPriority, priority field from ParsedPacket
- Renamed: dropLowestPriority() → dropOldestPacket()
- Simplified: All packets treated equally in FIFO queue
Diagnostic Marking: Unified format for temporary diagnostics
- Standard Format: === DIAGNOSTIC START === (Remove after MAVLink stabilization)
- Easy Removal: All diagnostic code clearly marked for future cleanup
TODO Addition: Added reminder for adaptive buffer minimum size analysis

v2.14.1 (CircularBuffer Deadlock Fix & Priority System Rollback) ✅

CircularBuffer Critical Fix

tail=511 Deadlock Resolution: Fixed critical issue where CircularBuffer would deadlock at buffer boundaries
- Root Cause: When tail near buffer end (e.g., tail=459 in 512-byte buffer), only 53 linear bytes available despite 511 total bytes
- Solution: Data linearization using tempLinearBuffer[296] for transparent wrap handling
- Impact: MAVLink parser now gets consistent contiguous view up to 296 bytes regardless of wrap position
Memory Optimization: Removed obsolete shadow buffer system
- Heap Savings: 296 bytes per buffer moved from heap to BSS (better for embedded)
- Cleaner Architecture: Eliminated non-functional shadow update logic from write() method
Simplified Consume Logic: Replaced complex boundary jump heuristics with clean consume pattern
- No More Boundary Jumps: Parser always consumes exactly bytesProcessed amount
- Eliminated Stuck States: No more aggressive consume or forced boundary jump workarounds

Priority System Rollback

Architecture Simplification: Rolled back from 4-priority queue system to single FIFO
- Removed Complexity: Eliminated CRITICAL/HIGH/NORMAL/BULK priority queues
- Single Queue: PacketSender now uses simple std::queue for all packets
- Simplified Enums: protocol_types.h reduced to PRIORITY_NORMAL only
Code Cleanup: Removed all priority-specific methods and logic
- Parser Simplification: MavlinkParser.getPacketPriority() now returns PRIORITY_NORMAL for all
- Sender Cleanup: Removed getDropped{Bulk,Normal,Critical} methods from UartSender/UdpSender
- TODO Comments: Added documentation for potential future priority reintroduction

Performance Improvements

MAVFtp Stability: File transfer now works reliably without progress rollbacks
Packet Loss Reduction: From 100+ losses per session to <1%
CRC Error Reduction: From 100+ CRC errors to <10 per session
High Speed Support: Stable operation at 921600 baud without packet corruption

v2.14.0 (PyMAVLink Migration & Architecture Cleanup) ✅

MAVLink Library Migration

PyMAVLink Integration: Complete migration to PyMAVLink for better compatibility and maintainability
- Library Replacement: Replaced previous MAVLink implementation with standard PyMAVLink
- Generated Headers: Full pymavlink integration (common + ardupilotmega dialects)
- Configuration: Updated build system with proper PyMAVLink compiler flags
- Improved Parsing: Enhanced MAVLink processing efficiency and reliability

Architecture Simplification

Protocol Detection Removal: Eliminated complex protocol detection system
- Removed Files: mavlink_detector.h/cpp, protocol_detector.h, protocol_factory.h/cpp
- Direct Parser Creation: Protocol pipeline now creates parsers directly based on configuration
- Simplified Logic: PROTOCOL_MAVLINK → MavlinkParser, PROTOCOL_NONE → RawParser
MAVLink Function Migration: Moved MAVLink-specific logic from pipeline to parser
- MavlinkParser Enhancement: Added non-MAVLink stream detection and warnings
- Smart Buffering: Parser handles invalid data gracefully with progress warnings
- Error Recovery: Automatic detection of non-MAVLink streams with user guidance

Code Structure Cleanup

types.h Optimization: Cleaned protocol structure from detection artifacts
- Removed Fields: detector pointer, minBytesNeeded (detection-specific)
- Preserved Fields: type, stats, enabled flag for runtime control
- Initialization: Proper protocol structure initialization in initBridgeContext()
Include Cleanup: Removed legacy library and detector includes across codebase
Factory Pattern Removal: Eliminated initProtocolDetectionFactory() and cleanup functions

Technical Improvements

Memory Efficiency: Reduced memory footprint by removing detection overhead
Processing Speed: Direct parser instantiation eliminates detection delays
Maintainability: Simplified codebase with clear parser responsibilities
Future Ready: Clean architecture for additional protocol support

v2.13.2 (Protocol Statistics Web Interface) ✅

Protocol Statistics Implementation

Unified Protocol Statistics: Complete web interface implementation for all protocol types
- RAW Protocol Statistics: Now shows detailed chunk processing, buffer usage, and output device metrics
- MAVLink Protocol Statistics: Enhanced packet detection stats with priority-based drop analysis
- Extensible Architecture: Ready for future SBUS and other protocol implementations

Web Interface Enhancements

Protocol Pipeline Integration: Centralized statistics through ProtocolPipeline.appendStatsToJson()
Dynamic Protocol Display:
- RAW mode shows "Chunks Created", buffer utilization, timing-based processing metrics
- MAVLink mode shows "Packets Detected", detection errors, resync events with precise packet analysis
- Automatic protocol type detection and appropriate UI rendering
Sender Statistics Table: Unified output device statistics with protocol-aware drop analysis
- MAVLink: Priority breakdown (Bulk/Normal/Critical packet drops)
- RAW: Percentage-based drop rate calculation
- Queue depth monitoring and maximum queue tracking

Backend Architecture

ProtocolPipeline Statistics: Added appendStatsToJson() method for unified data export
JSON Structure Standardization: Consistent protocol statistics format across all protocol types
Memory Efficient: Uses existing pipeline structures without additional allocations
ArduinoJson Integration: Proper JSON serialization for web interface consumption

Code Modernization

Eliminated Legacy Stats: Removed old protocol statistics code from web_api.cpp (~40 lines)
Modular JavaScript: Added specialized render methods for different protocol types
Responsive Design: Grid-based layout adapts to different screen sizes
Error Handling: Graceful fallback for unknown or future protocol types

Critical Fixes and Optimizations

Fixed Protocol Statistics Crashes: Added comprehensive null pointer checks in appendStatsToJson()
- Problem: Null pointer access causing packet losses and system instability
- Solution: Added checks for !ctx, !ctx->system.config before accessing pointers
- Result: Eliminated crashes during statistics export in web interface
Fixed RAW Parser Statistics: RAW protocol now properly updates statistics in web interface
- Problem: RAW parser showed zeros for all metrics despite active data processing
- Solution: Used existing updatePacketSize() and stats->reset() methods instead of creating new fields
- Result: Real-time statistics display for chunk processing, bytes transmitted, size ranges
Memory Pool Optimization: RAW parser now uses standard pool sizes for efficiency
- Problem: Arbitrary chunk sizes (98, 103, 115 bytes) caused "Pool exhausted" warnings
- Solution: Round allocation sizes to pool standards (64, 128, 288, 512 bytes) while preserving actual data size
- Result: Eliminated pool warnings, improved memory efficiency, reduced heap fragmentation
Statistics Reset Fix: "Reset Statistics" button now properly clears all protocol metrics
- Problem: New protocol fields not reset when user clicked reset button
- Solution: Enhanced reset() methods to clear all statistics fields including protocol-specific ones
- Result: Complete statistics reset functionality across all protocols

v2.13.1 (Statistics Synchronization Unification) ✅

Statistics Architecture Refactoring

Unified Statistics Management: Centralized all device statistics functions in diagnostics.cpp
- Problem Solved: Eliminated duplicate statistics functions across multiple files
- Core 0/Core 1 Separation: Clean separation by CPU cores for optimal performance
- Thread Safety: All device statistics properly synchronized using critical sections

Function Consolidation

Moved to diagnostics.cpp:
- updateMainStats() - Updates Device 1/2 statistics (Core 0 devices)
- updateDevice3Stats() - Updates Device 3 statistics (Core 1 device)
- updateDevice4Stats() - Updates Device 4 statistics (Core 1 device)
Removed Duplicate Code:
- Deleted updateMainStats() from uartbridge.cpp
- Deleted updateDevice3Stats() from device3_task.cpp
- Removed static pointer variables no longer needed
- Clean extern declarations in scheduler_tasks.cpp

Architecture Benefits

Proper Core Distribution:
- Core 0: Device 1 (UART1) + Device 2 (USB/UART2) → unified in updateMainStats()
- Core 1: Device 3 (UART3) + Device 4 (UDP) → separate functions for each
Reduced Race Conditions: Each device's statistics updated in single location
Better Maintainability: All statistics logic centralized in diagnostics module
Performance: Minimal blocking between cores, optimized update intervals

Device 4 Statistics Integration

BridgeContext Integration: Added Device 4 fields to main bridge context
Pipeline Statistics: UdpSender properly updates TX byte counters
Scheduler Tasks: Device 4 statistics task properly restored and configured
Global Variables: Maintained existing globalDevice4* variables for task communication

v2.13.0 (Protocol Architecture Refactoring) 🚀

Major Architecture Overhaul: Parser + Sender Pattern

Complete Protocol Architecture Redesign: Implemented separation of packet parsing and transmission
- New Data Flow: UART RX → CircularBuffer → Parser → PacketQueue → Sender(s) → Device(s)
- Problem Solved: Eliminated coupling between protocol detection and transmission logic
- Benefits: Clean architecture, better maintainability, protocol-agnostic design

Memory Pool Implementation

Slab Allocator: Thread-safe memory pool for packet management
- Implementation: packet_memory_pool.h with Meyers Singleton pattern
- Pool Sizes: 64B (control packets), 288B (MAVLink), 512B (RAW chunks)
- Fallback: Automatic heap allocation when pools exhausted
- Thread Safety: C++11+ guaranteed initialization safety

Protocol Pipeline Components

Parser Framework: Base ProtocolParser class with specialized implementations
- RawParser: Adaptive buffering without protocol parsing (default mode)
- MAVLinkParser: MAVLink packet boundary detection and parsing
- Future Ready: Architecture supports SBUS, CRSF protocol additions
Sender Framework: Priority-based packet transmission system
- UsbSender: Exponential backoff for congestion handling
- UartSender: Inter-packet gap support for timing-sensitive protocols
- UdpSender: Batching capabilities for network efficiency
- Priority Support: CRITICAL > NORMAL > BULK packet prioritization

Transmission Improvements

Backpressure Handling: Intelligent packet dropping based on priority levels
Partial Send Support: USB/UART senders handle incomplete transmissions
Queue Management: Per-sender packet queues with size limits
Flow Control: Ready state checking prevents buffer overflow

Integration & Cleanup

Pipeline Coordinator: ProtocolPipeline class manages all parsers and senders
Bridge Integration: Seamless integration with existing UART bridge task
Legacy Removal: Cleaned up old protocol detection functions
Code Quality: All comments converted to English, consistent style

Performance Benefits

Zero Copy: Direct buffer access for parsing without data copying
Memory Efficient: Pool allocation prevents heap fragmentation
Multi-core Ready: Thread-safe design for ESP32 dual-core operation
Scalable: Easy addition of new protocols and output devices

v2.12.1 (Memory Optimization & Final Code Cleanup) ✅

Memory Optimization Phase

Legacy Buffer Removal: Complete elimination of old buffer architecture
- Memory Saved: 384-2048 bytes of RAM (removed duplicate buffer allocation)
- Code Cleanup: Removed unused adaptiveBuffer allocation in uartbridge.cpp:95-98
- Architecture: Now uses only CircularBuffer implementation
- Validation: Ensured no remaining references to legacy buffer system

bufferIndex Removal Optimization

Structure Cleanup: Removed bufferIndex from AdaptiveBufferContext structure
- Memory Saved: Additional 8 bytes (pointer + int) per bridge context
- Code Paths: Eliminated all bufferIndex initialization and update code
- Critical Fix: Updated isBufferCritical() in protocol_pipeline.h:182-188
  - Before: Used legacy bufferIndex for buffer fullness detection
  - After: Direct CircularBuffer availability check: circBuf->available() >= bufferSize - 64
- Validation: Comprehensive search confirmed no remaining bufferIndex references

Production Code Cleanup

Debug Code Removal: All temporary diagnostic logging removed for production
- Files Cleaned: circular_buffer.h, main.cpp, adaptive_buffer.h
- Log Reduction: Removed verbose buffer initialization and operation logs
- Performance: Cleaner log output focused on critical events only
- Maintenance: Easy identification and removal of TEMPORARY DEBUG blocks

Final Architecture State

Single Buffer: CircularBuffer as the only data buffer implementation
Zero Waste: No duplicate memory allocations or unused legacy code
Clean Codebase: Production-ready with minimal diagnostic output
Memory Efficient: Optimized RAM usage through complete legacy removal

v2.12.0 (Circular Buffer Implementation & Adaptive Thresholds) 🚀

Major Architecture Changes

Circular Buffer Migration: Replaced legacy linear buffer with modern circular buffer
- Problem: Old buffer used inefficient memmove operations causing data corruption
- Solution: Zero-copy circular buffer with scatter-gather I/O
- Implementation:
  - New CircularBuffer class in src/circular_buffer.h
  - Power-of-2 sizing for bitwise masking (256-2048 bytes)
  - Shadow buffer (296 bytes) for protocol parsing continuity
  - Thread-safe with FreeRTOS portMUX locks
- Critical Fix: Added missing initAdaptiveBuffer() call in uartbridge.cpp
  - BridgeContext now properly initializes CircularBuffer
  - Fixed nullptr issue preventing data transmission

Adaptive Traffic Detection

Gap-based Traffic Detector: Automatic mode switching based on data patterns
- Normal Mode: Standard telemetry (2ms timeout, 10% buffer threshold)
- Burst Mode: Parameter downloads (5ms timeout, 20% buffer threshold)
- Detection Logic:
  - Fast data: <1ms gaps between bytes
  - Burst trigger: 100+ consecutive fast bytes
  - Burst end: >5ms pause in data stream
- Benefits: Optimizes for both low-latency telemetry and bulk transfers

USB Bottleneck Handling

Smart Drop Strategy: Prevents complete system hangs
- Thresholds (percentage-based, scales with buffer size):
  - Warning: 85% (small), 70% (medium), 60% (large)
  - Critical: 90% (small), 75% (medium), 65% (large)
- Drop Policy:
  - Warning level: Drop 12.5% after 5 retry attempts
  - Critical level: Drop 33% immediately
- Improvement: Better than old system which could hang indefinitely

Performance Optimizations

Transmission Thresholds:
- Normal: 128 bytes max (low latency priority)
- Burst: 200 bytes max (optimized for single MAVLink packet)
Buffer Sizes (auto-calculated based on baudrate):
- 115200: 288 bytes (384 with protocol)
- 230400: 768 bytes
- 460800: 1024 bytes
- 921600: 2048 bytes

Diagnostic Enhancements

Comprehensive Debug Logging (all marked TEMPORARY for easy removal):
- Buffer initialization and allocation
- Write operations and availability
- Transmission triggers with mode indication
- USB status and bottleneck events
- Segment information for scatter-gather
Traffic Statistics:
- Total bursts detected
- Maximum burst size
- Drop events and bytes

TODO.md Updates

Added Circular Buffer Optimizations (v2.6.x)
Added Protocol-aware Optimizations (v2.7.0)
Added USB Optimizations (v2.7.x)

Testing Recommendations

Low Traffic Test: Normal telemetry should show "NORMAL mode"
High Traffic Test: Parameter downloads should trigger "BURST mode"
USB Bottleneck Test: Monitor for controlled drops vs hangs
Success Metrics:
- Packet loss <5% (from 32+ events)
- CRC errors <20 (from 56)
- No transmission freezes
- Successful MAVLink parameter downloads

v2.11.0 (Project Restructuring & MAVLink Fix) ✅

Project Structure Reorganization: Improved code organization with dedicated folders
- Created subfolder structure: Organized related modules into logical directories
  - src/web/ - Web interface modules (web_api, web_interface, web_ota)
  - src/usb/ - USB implementation files (usb_device, usb_host, interfaces)
  - src/devices/ - Device tasks and initialization (device3_task, device4_task, device_init)
  - src/wifi/ - WiFi management (wifi_manager)
  - src/uart/ - UART and flow control (uart_dma, uartbridge, flow_control)
- Updated all include paths: Fixed 30+ files with new relative paths
  - Files within folders use local includes ("file.h")
  - Cross-folder includes use relative paths ("../folder/file.h")
  - Main files use folder paths ("folder/file.h")
- Benefits:
  - Better code navigation and maintainability
  - Clearer module boundaries and dependencies
  - Easier to locate related functionality
  - Reduced clutter in src/ root directory
MAVLink Parser Critical Fix: Resolved packet loss and CRC errors
- Root Cause: Parser state corruption from buffer operations
- Solution: Independent frame buffer approach with improved isolation
- Implementation: Enhanced parser with stable buffer management and simplified error handling
- Results:
  - Before: 547 packet losses, 349 CRC errors, 13314 detection errors
  - After: <1% packet loss, <10 CRC errors, <100 detection errors
  - MAVFtp file transfers now work reliably
  - Eliminated configuration-related parsing errors
- Code Cleanup:
  - Removed #include <map> and all std::map usage
  - Deleted methods: updateDetailedStats(), checkSequenceLoss(), logPacketInfo()
  - Simplified to basic error counters for diagnostics
  - Reduced memory footprint and complexity

v2.10.2 (USB Backpressure Reversion) ✅

USB Backpressure Simplification: Reverted complex behavioral detection to simple approach
- Removed Features: Complex behavioral port state detection system
  - Behavioral detection logic removed from src/usb_device.cpp
  - Dynamic thresholds (ASSUME_CLOSED_THRESHOLD, FIRST_ATTEMPT_THRESHOLD) eliminated
  - Port state tracking and related statistics removed
  - Automatic protocol detector reset on port changes disabled
- Root Cause: Stability issues and false positives on different systems
  - False port closure detection causing unnecessary data drops
  - System-dependent behavior making solution unreliable
  - Over-complexity for marginal benefit in real-world usage
- Current Implementation: Simple Arduino Serial backpressure
  - Basic Serial.availableForWrite() check retained
  - Buffer overflow prevention still functional
  - Improved stability across different USB host systems
  - Simpler debugging without complex state machine
- Decision Rationale:
  - Simple solution proved more reliable than complex behavioral detection
  - Arduino Serial backpressure sufficient for most use cases
  - Eliminated source of platform-specific issues
- Future Consideration: May revisit with simpler heuristics if specific need arises

v2.10.1 (Configuration Cleanup) ✅

USB Configuration Cleanup: Removed unsupported USB Auto mode
- Code Cleanup: Removed USB_MODE_AUTO enum value and all related handling code
- Web Interface: Removed "Auto (not supported)" option from USB mode selection
- Configuration: Simplified USB mode to only Device and Host options
- Implementation: Deleted UsbAuto class and createUsbAuto factory function
- Benefits: Cleaner codebase, no misleading configuration options

v2.10.0 (USB Buffer Overflow Prevention) ✅

USB Buffer Overflow Prevention: Behavioral port state detection to prevent buffer overflow
- Behavioral Port Detection (src/usb_device.cpp): Smart detection of USB port state without relying on unavailable APIs
  - Buffer monitoring: Tracks write buffer availability patterns to detect port closure
  - Adaptive thresholds: ASSUME_CLOSED_THRESHOLD (20) and FIRST_ATTEMPT_THRESHOLD (5) for optimal response
  - Honest API: Returns 0 when unable to write, allowing caller to manage data freshness
  - Automatic recovery: Seamless transition when port opens/closes
- Early Data Dropping (src/adaptive_buffer.h): Prevents accumulation of stale data
  - Connection state tracking: Monitors USB port state changes in real-time
  - Protocol detector reset: Automatic reset when port reopens to prevent packet fragmentation
  - Buffer cleanup: Immediate buffer clearing on port state transitions
  - Diagnostic integration: Proper statistics tracking for dropped data
- Improved Diagnostics: Enhanced meaning of UART FIFO overflow messages
  - Real issues only: FIFO overflow now indicates actual USB performance problems when port is open
  - Reduced log spam: Eliminated false overflow warnings when port is closed
  - Better troubleshooting: Clear distinction between port closure and performance issues
- Real-time Performance: Optimized for time-critical applications
  - Fast detection: ~20-200ms response time for port closure detection
  - Fresh data guarantee: Only current data transmitted after port reopens
  - Zero stale data: Prevents transmission of outdated information

v2.9.5 (Critical Memory Safety & Logging Refactoring) ✅

Critical Memory Safety Fixes: Eliminated heap corruption and segmentation faults
- Adaptive Buffer Protection (src/adaptive_buffer.h): Fixed buffer underflow and bounds checking
  - Underflow prevention: Added validation for totalConsumed > bufferIndex before size_t arithmetic
  - Bounds checking: Comprehensive validation before all memmove operations
  - Safe state recovery: Automatic buffer reset on detection of invalid states
  - Partial transmission safety: Enhanced partial data transmission with proper boundary checks
- Protocol Pipeline Hardening (src/protocols/protocol_pipeline.h): Fixed MAVLink detection crashes
  - Pointer validation: Added bounds checking before detector->canDetect() calls
  - Search window protection: Prevented buffer overruns during protocol packet search
  - Packet size validation: Limited packet sizes to reasonable bounds (max 512 bytes)
  - Diagnostic logging: Added periodic state dumps for debugging protocol issues
- MAVLink Detector Improvements (src/protocols/mavlink_detector.h/cpp): Enhanced error recovery
  - Increased search window: Expanded from 64 to 300 bytes for better resync capability
  - Improved resync logic: More efficient recovery from garbage data streams
  - Enhanced error handling: Better progress through invalid data sequences
- Stability Impact: Eliminated MAVFtp connection drops and system crashes
  - Zero heap corruption: Fixed root cause of ESP32 reboots during MAVLink processing
  - Reliable protocol detection: MAVLink packets now consistently detected and processed
  - Stable network operations: MAVFtp parameter uploads work without interruption
Logging System Refactoring: Complete elimination of heap fragmentation
- Printf-Style Migration: Migrated all ~306 log_msg calls across 21 files
  - Replaced String concatenation ("Text " + String(var)) with printf format ("Text %d", var)
  - Unified logging interface: log_msg(LOG_LEVEL, "format", args)
  - Added compile-time format string validation with __attribute__((format(printf, 2, 3)))
- Memory Optimization: Eliminated heap allocation in logging hot paths
  - Stack-based formatting: All log messages use 256-byte stack buffers
  - Zero heap fragmentation: Removed String object creation in critical paths
  - Hot path protection: Adaptive buffer and protocol pipeline logging optimized
- Performance Impact: Significant stability improvement for ESP32
  - Reduced RAM usage: Eliminated hundreds of String allocations per second
  - Lower fragmentation: ESP32 heap stays healthier during intensive operations
  - Better reliability: Reduced risk of memory-related crashes during MAVLink processing
- Code Cleanup: Removed deprecated logging functions
  - Deleted old log_msg(String, LogLevel) and log_msg(const char*, LogLevel) functions
  - Single unified printf-style logging function for entire codebase
  - Improved code maintainability and consistency

v2.9.0 (MAVLink Protocol Implementation) ✅

MAVLink Protocol Detector - Phase 4.2 Complete
- Core MAVLink Implementation: Full MAVLink v1/v2 packet detection
  - Created src/protocols/mavlink_detector.h/cpp with complete implementation
  - MAVLink packet boundary detection with header validation and payload size calculation
  - Support for MAVLink v1 (0xFE) and v2 (0xFD) protocol versions
  - Error handling with next start byte search for packet recovery
- Protocol Statistics System: Comprehensive performance tracking
  - Created src/protocols/protocol_stats.h for real-time metrics
  - Tracks detected packets, transmitted packets, error count, resync events
  - Packet size statistics (average, min, max) and transmission rates
  - Integration with web interface for live protocol monitoring
- Configuration Management: Seamless integration with existing config system
  - Added protocolOptimization field with version migration (v6→v7)
  - Protocol factory system with src/protocols/protocol_factory.h/cpp
  - Web interface dropdown for protocol selection (None/MAVLink)
  - Configuration persistence and loading across reboots
- Web Interface Enhancements: User-friendly protocol management
  - Protocol Optimization dropdown in main interface (after UART Configuration)
  - Collapsible Protocol Statistics section with real-time updates
  - Statistics display: packets, errors, sizes, rates, last packet timing
  - Form integration with save/load functionality
- Performance Impact: Dramatic latency reduction for MAVLink streams
  - Eliminates UART FIFO overflows at 115200 baud with high-speed MAVLink data
  - Instant packet transmission upon boundary detection (no timeout delays)
  - Perfect packet preservation - no data loss or fragmentation
  - Compatible with adaptive buffering fallback for non-MAVLink data
- HTML Minification Fix: Improved web interface readability
  - Disabled aggressive HTML minification to preserve text spacing
  - Maintained gzip compression for optimal size (70-78% reduction)
  - Preserved JavaScript/CSS minification for performance

v2.8.3 (Protocol Detection Framework) ✅

Protocol Detection Infrastructure - Phase 4.1 Complete
- Framework Architecture: Extensible protocol detection system
  - Created src/protocols/ directory with base classes and interfaces
  - Implemented ProtocolDetector interface for protocol-specific implementations
  - Added comprehensive protocol pipeline with processing hooks
- Data Structure Extensions: Enhanced core structures for protocol support
  - Added ProtocolType enum with support for MAVLink, Modbus RTU, NMEA, Text Line, SBUS
  - Extended BridgeContext with protocol detection state and error tracking
  - Added protocolOptimization configuration field with PROTOCOL_NONE default
- Integration Points: Protocol-aware data processing
  - Integrated protocol hooks in bridge_processing.h for byte-level processing
  - Enhanced adaptive_buffer.h with protocol-specific transmission logic
  - Added protocol lifecycle management in uartbridge.cpp
- Stub Implementation: Complete framework with zero functional impact
  - All protocol functions implemented as safe stubs returning default values
  - Zero performance overhead when disabled (PROTOCOL_NONE default)
  - Full backward compatibility with existing adaptive buffering
- Benefits: Ready infrastructure for Phase 4.2+ protocol implementations
  - Easy addition of new protocols without architectural changes
  - Clear separation of concerns between framework and protocol logic
  - Prepared for future protocol-specific optimizations

v2.8.2 (WiFi Manager ESP-IDF Migration) ✅

Complete WiFi Manager Migration - Completed
- Full ESP-IDF Implementation: Migrated from Arduino WiFi API to native ESP-IDF
  - Replaced WiFi.h with esp_wifi.h, esp_event.h, esp_netif.h
  - Event-driven architecture using ESP-IDF event handlers
  - Native WiFi configuration and state management
  - Eliminated temporary AP appearance in Client mode (main issue resolved)
- mDNS Service Implementation: Device discovery by hostname in Client mode
  - Added mdns.h support with CONFIG_MDNS_ENABLED=y
  - Generated unique hostnames using device name + MAC suffix (2 bytes)
  - Safe mDNS initialization outside event handler context
  - HTTP service advertisement for web interface discovery
- DHCP Hostname Configuration: Proper device identification in router
  - Implemented esp_netif_set_hostname() before WiFi start
  - Router now displays custom device name instead of "espresiff"
  - Hostname generation with MAC uniqueness for multiple devices
- Enhanced Error Handling: Robust connection management and recovery
  - Bootloop protection with safe mode after 3 WiFi init failures
  - Proper memory checks before WiFi initialization
  - Connection timeout handling and automatic retry logic
  - Scan failure recovery with WiFi subsystem reset

v2.8.1 (WiFi Client Mode Stability Fixes) ✅

WiFi Client Connection Logic - Major stability improvements
- AP Mode Conflict Resolution: Fixed dual AP+Client mode issue causing network conflicts
  - Added ESP-IDF level WiFi initialization with forced STA-only mode
  - Implemented double AP disable: at client start and after successful connection
  - Eliminated unwanted AP broadcast during client connection process
- Intelligent Connection Management: Enhanced retry logic with proper error distinction
  - Initial Connection: Scans every 15 seconds when network not found
  - Connection Attempts: Up to 5 attempts when target network is available
  - Authentication Failure: Stops after 5 failed attempts to prevent router lockout
  - Network Loss Recovery: Unlimited reconnection attempts after successful initial connection
  - Error State Handling: Clear distinction between "wrong password" and "network not found"
- LED Indication Accuracy: Corrected LED behavior for all connection states
  - Orange slow blink (2s): Searching for configured network
  - Orange solid: Successfully connected to WiFi network
  - Red fast blink (500ms): Authentication failed (wrong password) - restart required
  - Purple solid: AP mode active for direct configuration
- Performance Optimization: Eliminated unnecessary scanning after successful connection
  - Fixed continuous scanning loop when already connected
  - Improved WiFi manager process state handling
Code Quality Improvements
- ESP-IDF Integration: Hybrid approach using ESP-IDF for initialization, Arduino for operations
Documentation Updates
- README.md: Comprehensive WiFi Client section with detailed connection logic
- Help Page: Updated HTML help with key WiFi Client information and troubleshooting
- Troubleshooting: Enhanced problem resolution guide with specific LED state meanings

v2.8.0 (WiFi Client Mode Implementation) ✅

WiFi Client Mode - Full implementation completed
- Dual WiFi Modes: Support for both Access Point (AP) and Client (STA) modes
- WiFi Manager: Complete state machine with scanning, connecting, and error handling
- Triple Click Logic: Enhanced button logic for mode switching between Standalone/Client/AP
- LED Indication System:
  - Orange slow blink during network scanning (2s interval)
  - Solid orange when connected as WiFi client
  - Fast red blink for connection errors (500ms interval)
  - White blink for button click feedback in Client mode
- Device 4 Network Awareness: Proper WiFi connection waiting using EventGroup synchronization
- Temporary/Permanent Modes: Session-based temporary modes and persistent configuration
- Configuration: Full web interface integration for WiFi Client credentials
- NVS Optimization: Fixed preferences key length limitations (temp_net_mode)
- Benefits:
  - Connect to existing WiFi networks while maintaining AP functionality
  - Seamless mode switching without configuration loss
  - Visual feedback for all WiFi states and user interactions
  - Reliable network operations with proper synchronization

v2.7.3 (Configuration Import/Export + UI Improvements) ✅

Configuration Import/Export - Completed
- Export Configuration: Download current config as JSON file with unique filename
- Import Configuration: Upload JSON config file with validation and auto-reboot
- Web Interface: Added "Configuration Backup" section with Export/Import buttons
- Async Reboot Fix: Resolved reboot timing issues using TaskScheduler for delayed restart
- UI/UX Improvements: Proper status messages, progress bars, and error handling
- Benefits:
  - Quick device provisioning and configuration backup/restore
  - Share configurations between devices
  - No need to reconfigure after firmware updates
  - Reliable status display without "Failed to fetch" errors

v2.7.2 (Device 3/4 Code Refactoring) ✅

Device 3/4 Module Separation - Completed
- File Structure: Created independent device3_task.cpp/h and device4_task.cpp/h modules
- Code Reduction: Reduced uartbridge.cpp from 600+ to 240 lines (360+ lines moved)
- Architecture Improvement: Clear separation of device responsibilities for better maintainability
- Dependencies: Updated all cross-file includes and extern declarations
- Linker Fixes: Resolved device3Serial definition conflicts between modules
- Benefits:
  - Easier maintenance and development
  - Reduced file complexity and improved readability
  - Clear module boundaries for future expansion
  - Preserved all existing functionality without changes

v2.7.1 (Device 3/4 Statistics Unification) ✅

Statistics Thread Safety - Completed
- Device 4 Protection: Added critical sections for all TX/RX statistics updates
- Device 3 Migration: Moved from local variables to global variables approach
- Race Condition Fixes: Eliminated multi-threaded statistics conflicts
- Unified Architecture: Consistent statistics handling across Device 3 and Device 4
- TaskScheduler Integration: Implemented updateDevice3Stats() for periodic updates
- Benefits:
  - Thread-safe statistics under high data load
  - Reliable counters without "jumping" values
  - Maintainable unified codebase
  - Stable operation in concurrent scenarios

v2.7.0 (Device 4 Network Implementation) ✅

Device 4 Network Functionality - Completed
- Network Logger Mode: Send system logs via UDP (broadcast or unicast)
- Network Bridge Mode: Bidirectional UART<->UDP communication
- Configuration: Full web interface integration with IP/Port settings
- Statistics: Real-time TX/RX bytes and packet counters
- Architecture:
  - AsyncUDP library for network operations
  - Ring buffers for non-blocking data transfer
  - Task runs on Core 1 with web server
  - DMA-style approach for efficient data handling
- Integration:
  - Device 4 configuration saved/loaded with config version 5
  - Network Log Level enabled when Device 4 is active
  - Full statistics in web interface status display
  - Works in both standalone and network modes
- Technical Details:
  - 2KB buffers for logs and bridge data
  - 50ms task delay for low latency
  - Mutex protection for thread-safe buffer access
  - Forward declarations to resolve compilation order
- Fixed Issues:
  - Web interface now correctly displays selected Device 4 role
  - Removed duplicate role name transmission in config JSON

v2.6.0 (ESPAsyncWebServer Migration) ✅

Migrated to ESPAsyncWebServer - Completed
- Libraries: Updated to ESPAsyncWebServer v3.7.10 + AsyncTCP v3.4.5
- Template System: Changed from custom {{}} to built-in %PLACEHOLDER% processor
- API Migration: Converted all handlers to async (request parameter access, response sending)
- OTA Adaptation: Redesigned file upload handling for async server
- Architecture: Removed webServerTask - AsyncWebServer works without dedicated task
- Memory Benefits: Better resource usage, no blocking operations
- Performance: Non-blocking request handling, improved concurrent connections
- JavaScript Fixes: Fixed Reset Statistics and Clear Crash History button handling
- Diagnostics: Enhanced stack monitoring for WiFi/TCP tasks instead of web server task

v2.5.8 (Permanent Network Mode) ✅

Permanent Network Mode Implementation - Completed
- Added permanent_network_mode configuration parameter in Config structure
- Updated configuration version from 3 to 4 with automatic migration
- Web interface: Added checkbox in WiFi Configuration section
- Backend: Full configuration save/load support with proper validation
- Boot logic: Automatic permanent network mode detection in detectMode()
- Benefits:
  - Wi-Fi access point remains active until manually disabled
  - No timeout for permanent mode (only for triple-click temporary mode)
  - Configurable via web interface with clear user feedback
  - Backward compatible with existing configurations
Build System Enhancement - Completed
- Added update_readme_version.py script for automatic version synchronization
- Script automatically updates README.md badge with version from defines.h
- Integrated into PlatformIO build process as pre-build script
- Prevents version mismatches between firmware and documentation
- Fixed: Removed blocking exit(0) that prevented compilation and upload

v2.5.7 (Device Init Refactoring) ✅

Refactor Device Initialization - Completed
- Migrated uartbridge_init() from uartbridge.cpp to device_init.cpp
- Renamed uartbridge_init() to initMainUART() for consistency
- Migrated initDevices() from main.cpp to device_init.cpp
- Updated all function calls in main.cpp (2 occurrences)
- Removed function declarations from original locations
- Benefits:
  - Better code organization with all device init functions in one module
  - Consistent naming convention for initialization functions
  - Reduced file sizes: uartbridge.cpp (~55 lines), main.cpp (~30 lines)
- Technical details:
  - Added necessary includes: usb_interface.h, flow_control.h, freertos/semphr.h
  - Made g_usbInterface global (was static) for cross-module access
  - Added diagnostics.h include for helper functions
  - Total lines moved: ~85 lines to device_init module

v2.5.6 (Bridge Mode Renaming) ✅

Rename Device Modes to Bridge Modes - Completed
- Renamed DeviceMode enum to BridgeMode
- Renamed MODE_NORMAL to BRIDGE_STANDALONE
- Renamed MODE_CONFIG to BRIDGE_NET
- Updated all references across 11 source files
- Benefits:
  - Clear separation of bridge functionality vs network state
  - Future-ready for Device 4 permanent network modes
  - Better naming that accurately describes functionality
  - Flexible design supporting different network configurations
Update SystemState Structure - Completed
- Renamed wifiAPActive to networkActive
- Renamed wifiStartTime to networkStartTime
- Added isTemporaryNetwork flag for future Device 4 support
- Allows differentiation between setup AP (temporary) and permanent network modes
Update All User-Visible Text - Completed
- Changed "normal mode" to "standalone mode" throughout
- Changed "config mode" to "network mode" throughout
- Changed "WiFi configuration" to "network setup" where appropriate
- Simplified to just "Network Mode" (without "setup") for universal usage
- Updated help documentation and web interface
Implementation Details - Completed
- Total changes: ~60 occurrences across 11 files
- Added critical comment for _TASK_INLINE macro in scheduler_tasks.h
- All mode checks updated to use new enum values
- Function names updated (initNormalMode → initStandaloneMode, etc.)
- TaskScheduler functions renamed (enableRuntimeTasks → enableStandaloneTasks)
- Network timeout only active when isTemporaryNetwork=true

v2.5.5 (Adaptive Buffer Optimization) ✅

Fix FIFO Overflow at 115200 baud - Completed
- Identified root cause: increased buffer size (512 bytes) causing USB bottleneck
- Created graduated buffer sizing for smoother performance:
  - < 115200: 256 bytes (original size)
  - 115200: 288 bytes (optimal compromise)
  - 230400: 768 bytes
  - 460800: 1024 bytes
  - 921600+: 2048 bytes
- Results at 115200 baud:
  - Reduced FIFO overflow from constant to rare (3-8 times per test)
  - Improved packet loss from 25% to 2-10%
  - Parameter download success rate: 83% (5 out of 6 attempts)
- Determined 288 bytes as optimal for 115200 baud without flow control
Code Cleanup - Completed
- Fixed duplicated adaptive buffering code in bridge_processing.h
- Now properly uses functions from adaptive_buffer.h
- Removed ~55 lines of duplicated code
- Added temporary diagnostics (marked for removal after testing)

v2.5.4 (TaskScheduler Implementation) ✅

Implement TaskScheduler - Completed
- Added TaskScheduler library to replace manual timer checks
- Created scheduler_tasks.cpp/h for centralized task management
- Migrated all periodic tasks (diagnostics, statistics, LED updates)
- Saved ~100 lines of timer management code
- Benefits achieved:
  - Cleaner code structure
  - Easy to add/remove periodic tasks
  - Better timing accuracy
  - Reduced cognitive load
- All tasks properly distributed in time to prevent simultaneous execution
- Mode-specific task management (Runtime vs Setup modes)

v2.5.3 (Phase 2 Code Refactoring - Hybrid Approach) ✅

Phase 2 Refactoring - Hybrid Approach - Completed
- Further refactored uartbridge.cpp from ~555 to ~250 lines
- Created BridgeContext structure for clean parameter passing
- Maintained performance with static inline functions
Extended types.h - Completed
- Added comprehensive BridgeContext structure
- Groups all task-local variables logically
- Added inline initBridgeContext() function
- Forward declarations for UartInterface/UsbInterface
Enhanced Diagnostics Module - Completed
- Moved periodic diagnostics from uartbridge.cpp
- Added logBridgeActivity(), logStackDiagnostics()
- Added logDmaStatistics(), logDroppedDataStats()
- Created updatePeriodicDiagnostics() main function
- ~150 lines moved to diagnostics module
Created bridge_processing.h - Completed
- All data processing logic as inline functions
- processDevice1Input(), processDevice2USB/UART()
- processDevice3BridgeInput()
- shouldYieldToWiFi() helper
- ~200 lines of processing logic extracted
Created adaptive_buffer.h - Completed
- All adaptive buffering logic in one place
- shouldTransmitBuffer(), transmitAdaptiveBuffer()
- handleBufferTimeout()
- calculateAdaptiveBufferSize() moved from device_init
- ~120 lines of buffering logic extracted
Simplified Main Loop - Completed
- Clean, readable main loop with function calls
- All complex logic in specialized modules
- Performance preserved with inline functions
- Ready for future extensions

v2.5.2 (Phase 1 Code Refactoring) ✅

Refactor Large uartbridge.cpp File - Phase 1 Complete
- Original size: ~700 lines, reduced to ~555 lines
- Created modular structure without breaking functionality
Flow Control Module - Completed
- Created flow_control.h and flow_control.cpp
- Extracted detectFlowControl() and getFlowControlStatus() functions
- ~50 lines of code moved to separate module
- Clean separation of flow control logic
Device Initialization Module - Completed
- Created device_init.h and device_init.cpp
- Extracted initDevice2UART() and initDevice3() functions
- ~85 lines of code moved to separate module
- Fixed linkage issues with proper extern declarations
Build System Verification - Completed
- Fixed static/extern conflicts for device2Serial
- Added proper extern declarations in uartbridge.h
- Project compiles successfully with new structure
- All functionality preserved

v2.5.1 (Web Interface Modularization) ✅

Split main.js into modules - Completed
- Created separate JS modules for better organization:
  - utils.js - Common utility functions
  - device-config.js - Device configuration UI
  - form-utils.js - Form handling and validation
  - status-updates.js - Status and statistics updates
  - crash-log.js - Crash log handling
  - main.js - Main initialization and coordination
- Updated web_interface.cpp to serve all JS files
- Updated embed_html.py to process all JS files
- Added proper handlers in web_interface.h
Fix Reset Statistics button - Completed
- Removed confirmation dialog as requested
- Fixed button state stuck on "Resetting..."
- Button now properly returns to "Reset Statistics" after operation
OTA Update Safety - Completed
- Added Device 3 UART0 deinitialization before OTA update
- Prevents conflicts during firmware update when Device 3 uses UART0
- Made device3Serial accessible from web_ota.cpp
- Ensures clean OTA update even with active Device 3
Code Cleanup - Completed
- Removed unused lastWdtFeed variable from uartbridge.cpp
- Fixed legacy code remnants

v2.5.0 (Complete ESP-IDF Migration + Performance) ✅

Complete ESP-IDF Migration - Completed
- Migrated Device 2 UART to ESP-IDF/DMA ✅
- Migrated Device 3 UART to ESP-IDF/DMA ✅
- Migrated UART logger to ESP-IDF/DMA ✅
- Removed HardwareSerial dependencies completely ✅
- Removed serial_config_decoder.h ✅
DMA Polling Mode Implementation - Completed
- Added polling mode support to UartDMA class ✅
- Device 2/3 use polling mode (no event tasks) ✅
- Added pollEvents() method for non-blocking operation ✅
- Optimized for minimal resource usage ✅
Configuration Architecture Improvement - Completed
- Created UartConfig structure for UART parameters ✅
- Separated DMA configuration from UART configuration ✅
- Fixed scope conflicts with global config ✅
- Clean parameter passing without global dependencies ✅
Dynamic Adaptive Buffer Sizing - Completed
- Buffer size now adjusts based on baud rate (256-2048 bytes) ✅
- 256 bytes for ≤19200 baud
- 512 bytes for ≤115200 baud
- 1024 bytes for ≤460800 baud
- 2048 bytes for >460800 baud
- Prevents packet fragmentation at high speeds
- Maintains low latency at all speeds

v2.4.0 (ESP-IDF Migration) ✅

Remove Arduino Framework Dependencies for Device1 - Completed
- Migrated Device 1 UART to ESP-IDF driver with DMA
- Removed all conditional compilation (#ifdef USE_UART_DMA)
- Deleted uart_arduino.cpp wrapper
- Improved UART performance with hardware packet detection
Configuration System Update - Completed
- Updated Config struct to use ESP-IDF native types (uart_word_length_t, uart_parity_t, uart_stop_bits_t)
- Increased config version to 3 with automatic migration
- Added conversion functions between ESP-IDF enums and web interface strings
Code Cleanup and Optimization - Completed
- Created UsbBase class to eliminate code duplication between USB Host and Device
- Simplified UartInterface with direct ESP-IDF configuration
- Removed serial_config_decoder.h dependency for Device 1
- Improved error handling and logging
Performance Improvements - Completed
- Hardware DMA for Device 1 UART with packet boundary detection
- Zero-copy ring buffer implementation
- Reduced CPU usage through event-driven architecture
- Native ESP-IDF drivers for better performance
- Increased DMA buffers and task priority for high-throughput scenarios
USB Implementation Decision - Completed
- Kept Arduino Serial for USB Device (stable and sufficient)
- USB Host already uses ESP-IDF
- Created common base class for code reuse
- USB performance not critical compared to UART

v2.3.3 (Performance Optimization) ✅

UART Bridge Performance Fix - Completed
- Fixed packet drops during MAVLink parameter downloads
- Optimized device role checks with cached flags
- Removed repeated config.deviceX.role comparisons in critical loop
- Improved performance at 115200 baud and higher
Buffer Size Optimization - Completed
- Increased UART_BUFFER_SIZE from 256 to 1024 bytes
- Added Serial.setTxBufferSize(1024) for USB interface
- Removed baudrate condition - always use 1KB buffers
- Reduced WiFi yield time from 5ms to 3ms

v2.3.2 (Web Interface Migration) ✅

Web Interface Refactoring - Completed
- Migrated from embedded HTML strings to separate HTML/CSS/JS files
- Created build-time processing with embed_html.py script
- Reduced placeholders from 40+ to just {{CONFIG_JSON}}
- Separated JavaScript into main.js and crash-log.js
- HTML/CSS/JS files now editable with proper IDE support
- C++ code reduced by ~3000 lines

v2.3.1 ✅

Update Statistics System - Completed
- Replaced old bytesUartToUsb/bytesUsbToUart with per-device counters
- Added device1RxBytes/device1TxBytes, device2RxBytes/device2TxBytes, device3RxBytes/device3TxBytes
- Updated web interface to show statistics for all active devices
- Shows device roles in statistics display
Code Cleanup - Completed
- Moved updateSharedStats and resetStatistics to diagnostics module
- Removed legacy if (currentMode == MODE_NORMAL || currentMode == MODE_CONFIG) check
- Fixed deprecated ArduinoJson containsKey() warning
- Added helper functions getDevice2RoleName() and getDevice3RoleName()
Web Interface Updates - Completed
- Updated traffic statistics table to show per-device data
- Dynamic show/hide of device rows based on active roles
- Updated JavaScript to handle new JSON structure from /status endpoint
- Fixed "Never" display for last activity

v2.3.0 ✅

Remove DEBUG_MODE - Completed
- Removed all DEBUG_MODE checks from code
- Bridge always active in all modes
- Diagnostics converted to log levels
Remove CONFIG_FREERTOS_UNICORE - Completed
- Now only supports multi-core ESP32
- UART task on core 0, Web task on core 1
Code Organization - Completed
- Extracted diagnostics to separate module (diagnostics.cpp/h)
- Moved system utilities to system_utils.cpp/h
- Moved RTC variables and crash update to crashlog.cpp/h
- main.cpp reduced from ~600 to ~450 lines

Current Status Summary

The project now uses a full ESP-IDF approach for all UART operations and modern AsyncWebServer:

Device 1 (Main UART): Full ESP-IDF with DMA and event task ✅
Device 2 (Secondary): ESP-IDF with DMA polling mode ✅
Device 3 (Mirror/Bridge/Log): ESP-IDF with DMA polling mode ✅
USB Device: Arduino Serial (proven stable) ✅
USB Host: ESP-IDF implementation ✅
UART Logger: ESP-IDF with DMA polling mode ✅
Permanent Network Mode: Fully implemented and configurable ✅
Web Server: ESPAsyncWebServer for non-blocking operations ✅

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CHANGELOG

v2.19.1

Web Terminal

v2.19.0

New Feature

MP Plugin (v2.3.0)

Web Flasher

Docs

v2.18.15

New Feature

Improvement

Bug Fix

Web Interface

Code Cleanup

Diagnostics

Documentation

Build & Release

v2.18.14

Web Interface

LED Indication

Web Interface

BLE Support

Code Cleanup

Build & Release

WiFi

Fixes

v2.18.13

MiniKit Build Split

Build System

Web UI Fixes

v2.18.12

Web UI

SBUS Conversion

MiniKit LED

v2.18.12-prev

New Features

MiniKit Bluetooth

MiniKit Memory Optimization

MiniKit Fixes

Code Quality

Web UI

Mission Planner Plugin

v2.18.11

New Features

Fixes

Documentation

Web UI

ESP32 MiniKit (WROOM-32) Support

Web UI

v2.18.10

New Features

Web UI

Fixes

Code Quality

v2.18.9 (WiFi & Configuration Improvements)

WiFi Enhancements

Web UI Improvements

Configuration Management

Code Quality

v2.18.8 (Build Automation & Code Cleanup)

CI/CD Improvements

Bug Fixes

Code Quality

Dependency Updates

v2.18.7 (Coredump to Flash - Crash Analysis) 🟢 COMPLETED

Core Dump System

Crash Log Enhancements

Debug Tools

Technical Implementation

Documentation

Code Quality Improvements

Dependency Updates

Bug Fixes

Known Issues