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Hardware Setup Guide

Bill of Materials (BOM)

Core RF Detection Modules

Component Quantity Specifications Approx. Cost
ESP32 DevKit 1 240MHz dual-core, WiFi/BT, 520KB RAM $5-10
CC1101 Module 1 300-928MHz transceiver $3-5
NRF24L01+ Module 1 2.4GHz transceiver with PA+LNA $2-4
RX5808 Module 1 5.8GHz video receiver $3-5
OLED Display 1 128x64 I2C SSD1306 $3-5

New Feature Modules (6 Enhancements)

Component Quantity Specifications Purpose Approx. Cost
GPS Module NEO-6M/7M 1 UART, 1Hz-10Hz update rate Geolocation tracking $8-12
LoRa SX1276 Module 1 915MHz, LoRa modulation Meshtastic mesh $6-10
MicroSD Card Module 1 SPI interface, supports up to 32GB Data logging $2-4
MicroSD Card 1 8-32GB Class 10 Log storage $5-10

Supporting Components

Component Quantity Specifications Approx. Cost
Breadboard/PCB 1 For prototyping $2-5
Jumper Wires 40+ Male-to-female, various lengths $3-5
Power Supply 1 5V 3A USB or LiPo 3.7V 2000mAh $8-15
Antennas (900MHz) 1 8.2cm wire or helical $2-5
Antennas (2.4GHz) 1 Dipole or PCB antenna $3-6
Antennas (5.8GHz) 1 Cloverleaf RHCP/LHCP $5-10
Antennas (915MHz LoRa) 1 8.6cm wire or helical $3-6
GPS Antenna 1 Passive ceramic patch $3-8

Total Cost: ~$70-130 USD (with all 6 new features)

Wiring Diagram

See wiring_diagram.svg for visual reference.

Step-by-Step Assembly

1. ESP32 Preparation

  • Connect ESP32 to breadboard
  • Ensure 3.3V and GND rails are accessible
  • IMPORTANT: ESP32 GPIO pins are 3.3V tolerant only!

2. SPI Bus Wiring (Shared)

Connect the following pins from ESP32 to ALL three RF modules:

ESP32 Pin Signal Connect To
GPIO 23 MOSI CC1101 MOSI, NRF24 MOSI, RX5808 MOSI
GPIO 19 MISO CC1101 MISO, NRF24 MISO, RX5808 MISO
GPIO 18 SCK CC1101 SCK, NRF24 SCK, RX5808 SCK
3.3V VCC All modules VCC
GND GND All modules GND

3. Chip Select (CS) Pins

Each SPI device needs a unique CS pin:

Module ESP32 CS Pin Module CS Pin Tier
NRF24L01+ GPIO 15 CSN Base+
CC1101 GPIO 5 CSN/SS Standard+
RX5808 GPIO 13 CS Standard+
LoRa SX1276 GPIO 26 NSS Pro
SD Card GPIO 27 CS Pro

4. NRF24L01+ CE Pin

ESP32 Pin NRF24 Pin
GPIO 2 CE

5. RX5808 RSSI Pin

ESP32 Pin RX5808 Pin
GPIO 34 (ADC) RSSI

6. OLED Display (I2C)

ESP32 Pin OLED Pin
GPIO 21 SDA
GPIO 22 SCL
3.3V VCC
GND GND

7. GPS Module (UART2)

ESP32 Pin GPS Pin
GPIO 16 TX (GPS transmit)
GPIO 17 RX (GPS receive)
3.3V VCC
GND GND

Note: GPS module TX connects to ESP32 RX and vice versa.

8. MicroSD Card Module (SPI)

ESP32 Pin SD Card Pin
GPIO 23 MOSI
GPIO 19 MISO
GPIO 18 SCK
GPIO 27 CS
3.3V VCC
GND GND

9. LoRa SX1276 Module (SPI)

ESP32 Pin LoRa Pin
GPIO 23 MOSI
GPIO 19 MISO
GPIO 18 SCK
GPIO 26 NSS/CS
GPIO 33 DIO0
GPIO 32 DIO1
GPIO 25 RST
3.3V VCC
GND GND

10. Optional Peripherals (Alerts & Power)

ESP32 Pin Component Description
GPIO 4 Passive Buzzer PWM audio alerts
GPIO 2 LED Visual threat indicator
GPIO 36 Battery ADC Voltage divider (100k/100k) for 4.2V lipo

Module-Specific Notes

CC1101 (900 MHz RF)

  • Antenna: Requires 868/915MHz antenna (wire length ~8.2cm for 915MHz)
  • Power: Draws ~15mA in RX mode, ~30mA in TX mode
  • Voltage: 1.8-3.6V (3.3V recommended)
  • Range: Up to 500m line-of-sight

NRF24L01+ (2.4 GHz RF)

  • Antenna: Built-in PCB antenna or external SMA
  • Power: PA+LNA version draws up to 115mA in TX mode
  • Voltage: 1.9-3.6V (3.3V recommended)
  • Note: Use 10µF capacitor between VCC and GND if experiencing instability
  • Range: Up to 1000m with PA+LNA version

RX5808 (5.8 GHz Video)

  • Antenna: Requires 5.8GHz antenna (cloverleaf or patch)
  • Power: ~100mA typical
  • Voltage: 5V input (has onboard 3.3V regulator)
  • Note: Connect VCC to ESP32 5V pin (VIN), not 3.3V
  • Channels: 40 channels across 5 bands (Raceband, Fatshark, etc.)

OLED Display (I2C)

  • I2C Address: Usually 0x3C or 0x3D
  • Power: ~20mA
  • Voltage: 3.3V or 5V compatible
  • Resolution: 128x64 pixels monochrome

GPS Module NEO-6M/7M (UART)

  • Protocol: NMEA 0183 standard
  • Update Rate: 1Hz default (configurable up to 10Hz)
  • Accuracy: 2.5m CEP (Circular Error Probable)
  • Cold Start: ~27 seconds
  • Hot Start: ~1 second
  • Power: ~45mA active, ~10mA backup
  • Voltage: 3.3V or 5V compatible
  • Antenna: Requires passive ceramic patch antenna (included with most modules)

MicroSD Card Module (SPI)

  • Supported Cards: MicroSD, MicroSDHC (up to 32GB)
  • File System: FAT16, FAT32
  • Power: ~80mA during write operations
  • Voltage: 3.3V or 5V with level shifter
  • Speed: SPI mode up to 25MHz
  • Note: Format card as FAT32 before first use

LoRa SX1276 Module (SPI)

  • Frequency: 915MHz (US) or 868MHz (EU)
  • Modulation: LoRa, FSK, OOK
  • Sensitivity: -148dBm (SF12, 125kHz BW)
  • Output Power: +20dBm (100mW) maximum
  • Range: Up to 10km line-of-sight
  • Power: ~120mA TX mode, ~10mA RX mode
  • Voltage: 3.3V
  • Antenna: Requires 915MHz helical or wire antenna (8.6cm)
  • Protocol: Meshtastic compatible

Power Considerations

Total Current Draw (All Features Enabled):

  • ESP32: ~160mA (WiFi active), ~240mA (WiFi + BLE scanning)
  • CC1101: ~30mA
  • NRF24L01+: ~115mA (TX mode)
  • RX5808: ~100mA
  • OLED: ~20mA
  • GPS Module: ~45mA
  • SD Card: ~80mA (write operations)
  • LoRa SX1276: ~120mA (TX mode)
  • Total Peak: ~770mA (all modules transmitting simultaneously)
  • Typical Average: ~350-450mA (normal operation)

Recommended Power Supply:

  • USB: 5V 3A adapter (recommended for bench testing)
  • Battery: LiPo 3.7V 2000-3000mAh with 5V boost converter
  • Portable: 18650 battery holder (2S configuration) with buck converter

Battery Life Estimates (2500mAh LiPo):

  • Continuous operation: ~5-6 hours
  • Low-power mode (GPS off, no logging): ~8-10 hours
  • Deep sleep between scans: ~24+ hours

Antenna Recommendations

900 MHz (CC1101)

  • Type: Quarter-wave wire antenna
  • Length: 8.2cm for 915MHz
  • Gain: 0-2dBi

2.4 GHz (NRF24L01+)

  • Type: PCB antenna (built-in) or external dipole
  • Gain: 2-5dBi (PA+LNA version)

5.8 GHz (RX5808)

  • Type: Cloverleaf (RHCP/LHCP) or patch antenna
  • Gain: 2-8dBi
  • Connector: SMA or RP-SMA

Enclosure Design

Recommended enclosure specifications:

  • Material: ABS plastic or 3D-printed PLA
  • Dimensions: 120mm x 80mm x 40mm minimum
  • Features:
    • Antenna ports (SMA bulkhead connectors)
    • Ventilation holes for heat dissipation
    • OLED display cutout
    • USB access for programming/power

Testing Procedure

  1. Visual Inspection: Check all connections for shorts
  2. Power Test: Connect power, verify 3.3V on all module VCC pins
  3. Serial Monitor: Upload firmware, check initialization messages
  4. Module Detection: Verify each RF module responds (check serial output)
  5. RSSI Test: Place active 2.4GHz device nearby, verify detection on NRF24
  6. Display Test: Confirm OLED shows signal bars

Troubleshooting

Problem Possible Cause Solution
ESP32 won't boot GPIO0 pulled low Check wiring, ensure GPIO0 is floating
Module not detected SPI wiring error Verify MOSI/MISO not swapped
NRF24 unstable Power supply noise Add 10µF capacitor near VCC pin
RX5808 no signal Wrong voltage Ensure RX5808 VCC connected to 5V
OLED blank Wrong I2C address Try 0x3C or 0x3D in code

Safety Warnings

⚠️ RF Exposure: Keep antennas at least 20cm from body during operation.

⚠️ ESD Protection: Handle modules with anti-static precautions.

⚠️ Overheating: Ensure adequate ventilation, especially for PA+LNA modules.

Next Steps

After hardware assembly, proceed to Software Configuration.