Curb Energy Monitor — Local web interface

Replaces the Curb cloud dependency with a fully local web interface and direct MQTT publishing to Home Assistant. No cloud account needed — everything runs on the device.

Disclaimer: This project is an independent, community-made tool. It is not affiliated with, endorsed by, or supported by Curb (efergy Technologies, LLC) in any way. Use at your own risk. Modifying your Curb device may void your warranty.

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What's new in v2.1

Feature	Page
ESP32 AMS integration — live L1/L2/L3 voltage, current, import/export power and power factor from AMS meter via amsreader-firmware over USB serial	arduino.html
HA auto-discovery for AMS — 9 MQTT sensors: voltage, current, power per phase	serial-reader.lua

Connecting an ESP32 with amsreader-firmware

UtilitechAS/amsreader-firmware reads the AMS HAN port and normally publishes data to MQTT. By adding a small patch to AmsToMqttBridge.cpp, it also outputs a compact JSON line on USB serial (UART0) after each meter reading:

{"u1":230.5,"u2":231.2,"u3":229.8,"i1":5.12,"i2":3.08,"i3":4.71,"p":2140,"px":0,"pf":0.98}

Requirements:

• ESP32-DevKitC (or similar) with CP2102 USB-UART (cp210x driver already included in modules/bin/)
• HAN port wired to GPIO16 (UART2 RX) — do not use GPIO3/RX0 (conflicts with USB serial)
• Curb USB hub with cp210x module loaded

Patch summary (src/AmsToMqttBridge.cpp):

// 1. Add global (after setupMode):
bool serialShared = false;

// 2. In setup(), after "bool shared = false;" block:
serialShared = shared;

// 3. In handleDataSuccess(), after meterState.apply(*data):
if (!serialShared) {
    Serial.printf("{\"u1\":%.1f,\"u2\":%.1f,\"u3\":%.1f,"
        "\"i1\":%.2f,\"i2\":%.2f,\"i3\":%.2f,"
        "\"p\":%d,\"px\":%d,\"pf\":%.3f}\n",
        meterState.getL1Voltage(), meterState.getL2Voltage(), meterState.getL3Voltage(),
        meterState.getL1Current(), meterState.getL2Current(), meterState.getL3Current(),
        (int)meterState.getActiveImportPower(),
        (int)meterState.getActiveExportPower(),
        meterState.getPowerFactor());
}

Add "device_type": "amsreader" to the ESP32 entry in /data/serial-devices.json on the Curb device. serial-reader.lua auto-detects the format and publishes to <base_topic>/ams/* on MQTT.

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What's new in v2.0

Feature	Page
Web terminal — full SSH-like terminal in the browser, Tab-completion, command history	cli.html
Arduino / Serial monitor — live serial output from Arduino/ESP32 over USB	arduino.html
Live measurement list — per-circuit W/A/V/PF table with one-click PDF print	kursliste.html
Kernel module manager — load/unload USB drivers, toggle boot persistence	modules.html
USB file manager — browse, upload, download and manage files on /data/sd/	usb.html
WiFi configuration — scan for networks and connect from the browser	wifi.html
Pre-compiled USB drivers — cdc-acm, ch341, cp210x for Linux 3.16.0-karo	modules/bin/
Serial reader — multi-device USB serial reader managed by hm	serial-reader.lua

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Screenshots

Dashboard — live power per circuit, grouped by CT, with distribution chart

Statistics — daily kWh per circuit as donut charts, hourly bar chart, period selector (day/week/month/year)

Calibration — per-circuit scale factors, live A readings, 0A reset

Settings — MQTT broker, credentials and device name

System info — device info, storage, memory, CPU load, network interfaces, PLC link quality

Serial & Powerline guide — J6 connector pinout, USB-serial wiring, PLC bridge instructions

Arduino / Serial monitor — live data from Arduino Mega over USB, temperature sensors and current per circuit

Web terminal — run commands directly on the Curb device from the browser

Live measurement list — per-circuit table with address, meter number and live A readings, PDF print

Kernel module manager — load/unload USB drivers, autoload toggle for boot persistence

USB file manager — storage status, format, mount/unmount and file transfer

WiFi configuration — scan for networks, connect/disconnect, autostart at boot

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What this does

Before	After
Curb → Curb Cloud → curb-to-mqtt.py → MQTT	Curb → MQTT direct
Web interface via Curb Cloud	Web interface local on device
Calibration in cloud config	Calibration via browser
MQTT config hardcoded in Python	MQTT config via browser
No local energy statistics	Daily kWh accumulation on device, historical archive

Requirements

• Curb Energy Monitor (NXP i.MX28, Linux 3.16.0, LuaJIT 2.0.4)
• SSH access to root@<curb-ip> (password or SSH key)
• MQTT broker on the network (e.g. Mosquitto on Home Assistant)
• Git Bash on Windows (not CMD or PowerShell) — download Git for Windows

Based on: codearranger/curbed — reverse-engineered documentation of the Curb IPC queue protocol, sampler data format, and Lua environment.

⚡ Before running install.sh — set up SSH

install.sh connects to Curb ~10 times. Without setup you will be prompted for the password 10 times. Already have an SSH key set up? Leave the password blank when prompted — install.sh will use your existing key automatically. Choose one of these options first:

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Option A — SSH key (recommended, free, one-time setup)

# Run once from Git Bash
ssh-keygen -t ed25519 -f ~/.ssh/curb_key -N ""
ssh-copy-id -i ~/.ssh/curb_key.pub root@<curb-ip>

After this: bash install.sh — no password prompt at all. If you already have a key on the device, skip this step and just leave the password blank when install.sh asks.

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Option B — sshpass (password stored in memory, one prompt)

1. Download sshpass.exe from https://github.com/diyism/sshpass-for-windows/releases
2. Place the file in C:\Program Files\Git\usr\bin\
3. Verify: command -v sshpass should return a path

After this: bash install.sh — prompts for password once at the top, reused automatically.

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Option C — no setup

bash install.sh works, but you will type the password ~10 times.

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Installation

git clone https://github.com/vegard1977/curb-local
cd curb-local
bash install.sh              # Prompts for IP interactively
bash install.sh <curb-ip>    # Or give IP as argument

The script will:

1. Create a backup of all files it modifies (saved on the device under /data/backup-<date>/)
2. Upload Lua scripts to /data/lamarr/
3. Deploy web pages to /data/sd/www/ (persistent) and /tmp/www/ (live)
4. Prompt for MQTT credentials if mqtt-config.json is missing
5. Patch /etc/hm.conf with new process entries
6. Patch /usr/local/bin/curb_status.sh so web pages survive reboots

A log file (install-YYYYMMDD-HHMMSS.log) is written to the project folder for debugging.

MQTT config

Copy the template and fill in your values — never commit mqtt-config.json (it is in .gitignore):

cp mqtt-config.json.example mqtt-config.json
# Edit mqtt-config.json with your values

Alternatively: edit directly in the browser via http://<curb-ip>/settings.html.

Web interface

Page	URL	Description
Dashboard	http://<curb-ip>/energy.html	Live power per circuit, W/A/V/PF, group totals
Statistics	http://<curb-ip>/stats.html	Daily kWh donut charts + hourly bar chart, period selector
Calibration	http://<curb-ip>/calibration.html	Scale factors, live readings, 0A reset
Settings	http://<curb-ip>/settings.html	MQTT broker, credentials, device name, file upload
System	http://<curb-ip>/sysinfo.html	Uptime, memory, storage, network, PLC link quality
Serial / Powerline	http://<curb-ip>/serial-guide.html	J6 pinout, USB-serial wiring, PLC bridge guide
Arduino / Serial	http://<curb-ip>/arduino.html	Live serial monitor for Arduino/ESP32, send commands
Web terminal	http://<curb-ip>/cli.html	Full terminal in browser — Tab-completion, command history
Live measurements	http://<curb-ip>/kursliste.html	Per-circuit W/A/V/PF table with PDF print
Kernel modules	http://<curb-ip>/modules.html	Load/unload USB drivers from browser
USB files	http://<curb-ip>/usb.html	Browse, upload, download and manage files on /data/sd/
WiFi	http://<curb-ip>/wifi.html	Scan and connect to WiFi networks

Dashboard

Live power consumption per circuit — updated every second. Shows W, A, V, PF and totals per CT group. Pie chart shows power distribution across the three CT groups.

Statistics

Energy statistics accumulated continuously on the device — independent of whether a browser is open.

• Donut charts — kWh per circuit for each of the three CT groups
• Hourly bar chart — kWh per hour for the current day (24 bars)
• Period selector — switch pie charts between Day / Week / Month / Year using history.json
• Resets automatically at midnight; historical data survives reboots

Calibration

Connect a known reference measuring device (e.g. Fluke) to a circuit and press Calculate — a new scale factor is computed automatically. All 18 CTs are shown with live values. Supports 0A calibration (mute a circuit with no load).

Settings

MQTT broker, username, password, base topic and device name — edit and save directly from the browser. Changes take effect after mqtt-streamer restarts (automatic via hm).

File upload — drag-and-drop or click to upload files directly to the Curb device (no SSH needed):

• HTML pages and images → /data/sd/www/ (active immediately, survives reboots)
• mqtt-streamer.lua or api-server.lua → /data/lamarr/ (streamer auto-restarts)

System info

• Device info: serial number, hardware version, OS version
• Storage bars for /data (configs, statistics) and /data/sd (web pages, logs)
• Memory usage bar and CPU load averages
• Network: IP address, per-interface state, MAC, RX/TX traffic, drop count
• Powerline (PLC): connected node MAC and TX/RX signal quality in dB
• Process status: sampler, streamer, api-server

Serial / Powerline guide

Instructions for connecting a USB-serial adapter to the Curb J6 debug port — useful for reading boot logs, debugging, or accessing the device without network.

Also covers the built-in powerline (PLC) bridge: the Curb uses a Qualcomm QCA7000 HomePlug AV chipset, so a compatible powerline ethernet adapter plugged into the same electrical circuit gives wired LAN access without running new cables.

J6 pinout (2.54 mm pitch, 3.3 V logic — located on the main PCB):

Pin	Signal
1	GND
2	TX (Curb → adapter)
3	RX (adapter → Curb)
4–6	NC

Connect TX→RX and RX→TX on a 3.3 V USB-serial adapter (CP2102, CH340, FTDI). Baud rate: 115200, 8N1. The serial console appears on /dev/ttymxc1 on the device.

Arduino / Serial monitor

Live serial output from any USB-connected Arduino, ESP32 or similar device. serial-reader.lua manages all configured ports via select() for non-blocking parallel reads. Configure ports and baud rates in /data/serial-devices.json (or via the web interface).

Web terminal

Full SSH-like terminal in the browser — runs commands on the Curb device and streams output live. Supports Tab-completion, command history (↑/↓), and ANSI colour. Useful for troubleshooting without needing an SSH client.

Live measurements

Sortable per-circuit table of live W/A/V/PF readings with group subtotals. One-click PDF print generates a formatted measurement report — useful for documenting a circuit panel.

Kernel module manager

Manage USB kernel drivers from the browser: load/unload modules and toggle boot persistence. Pre-compiled drivers for Linux 3.16.0-karo are included in modules/bin/: cdc-acm, ch341, cp210x, usbserial (supports Arduino Uno/Mega, ESP32, CH340 clones).

USB file manager

Browse, upload, download, rename and delete files on /data/sd/. Also supports formatting the USB partition and moving files between directories — useful for managing web pages, logs and config files without SSH.

WiFi configuration

Scan for nearby access points and connect/disconnect from the browser. Shows signal strength (dBm), current connection status and assigned IP.

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Architecture

[ADE7816 chip]
     |
[sampler.lua]  <-- managed by hm (health monitor), writes to IPC queue
     |
     +-- queue 1234 (STREAMER) --> [original streamer.lua]
     +-- queue 5678 (LEGACY)  --> [mqtt-streamer.lua]
                                      |
                                      +-- MQTT publish --> broker --> Home Assistant
                                      +-- /tmp/www/latest.json  --> Dashboard
                                      +-- /tmp/www/daily.json   --> Statistics (today)
                                      +-- /tmp/www/history.json --> Statistics (history)
                                      +-- /tmp/www/sysinfo.json --> System info (10 s)
                                      |
                               [api-server.lua] (port 8080)
                                      |
                                      +-- GET /api/data           --> latest.json
                                      +-- GET/POST /api/calibration
                                      +-- GET/POST /api/mqtt

Files on the Curb device

File	Description
/data/lamarr/mqtt-streamer.lua	MQTT publishing, kWh accumulation, sysinfo writer
/data/lamarr/api-server.lua	REST API for web interface (port 8080)
/data/lamarr/serial-reader.lua	Multi-device USB serial reader
/data/calibration.json	ADE7816 scale factors (editable via browser)
/data/mqtt-config.json	MQTT credentials (chmod 600, never in git)
/data/serial-devices.json	Serial port config for serial-reader.lua
/data/daily.json	Today's kWh per circuit + hourly totals (survives reboots)
/data/history.json	Per-circuit kWh archive, one entry per day, max 365 days
/data/sd/www/	Persistent storage of web pages and images
/tmp/www/	Active web root (lighttpd, populated from /data/sd/www/ on boot)
/tmp/www/sysinfo.json	System stats written every 10 s by mqtt-streamer
/lib/modules/3.16.0-karo/kernel/drivers/usb/*/	USB kernel drivers (cdc-acm, ch341, cp210x…)
/etc/init.d/S35modules	Boot init script — loads modules listed in curb-modules.conf
/etc/curb-modules.conf	List of .ko paths to load at boot (managed by modules.html)

Backup and restore

install.sh automatically creates a backup in /data/backup-<date>/ on the device.

Restore manually

ssh root@<curb-ip>

# List backups
ls /data/backup-*/

# Restore a file
cp /data/backup-<date>/hm.conf /etc/hm.conf

# Stop new processes and let hm clean up
kill $(ps | grep mqtt-streamer | grep lua | sed 's/^ *//' | cut -d' ' -f1) 2>/dev/null
kill $(ps | grep api-server    | grep lua | sed 's/^ *//' | cut -d' ' -f1) 2>/dev/null

Files modified by install.sh

File	Change
/etc/hm.conf	Adds mqtt streamer, api server and serial reader process entries
/usr/local/bin/curb_status.sh	Copies all 12 HTML pages + images on each boot
/data/lamarr/mqtt-streamer.lua	New file (replaces curb-to-mqtt.py)
/data/lamarr/api-server.lua	New file
/data/lamarr/serial-reader.lua	New file
/data/calibration.json	Only if absent
/data/mqtt-config.json	Only if absent
/data/serial-devices.json	Only if absent (uploaded from example)

Home Assistant auto-discovery

mqtt-streamer.lua sends 72 MQTT retained discovery messages on startup (18 circuits × 4 sensors: W, A, PF, V). Devices appear automatically in HA under Settings → Devices & Services → MQTT.

Discovery topic format:

homeassistant/sensor/curb_<serial>/curb_<serial>_circuit_N/config

Calibration

The ADE7816 chip has all VGAIN/IGAIN/WGAIN registers set to 0 in firmware. All calibration is done in software via /data/calibration.json:

• volt_scale — voltage: measure reference / raw ADC value
• watt_scale — power: calibrate against a known load
• pf_scale — 1/32768 (Q15 format, constant)
• circuit_current_scales[n] — individual CT calibration per circuit

Credits

This project would not have been possible without the reverse engineering work done by codearranger/curbed, which documented the Curb internal IPC queue protocol, sampler data format, and Lua runtime environment.

License

MIT