Flashing Firmware

Prerequisites

• ESP-IDF v5.x installed
• ESP32-CAM-MB carrier board (recommended) or USB-to-serial adapter
• LoRa module disconnected from GPIO 1/3 during flashing

Build for hardware

# Use the hardware sdkconfig defaults
cp sdkconfig.defaults sdkconfig.defaults
idf.py set-target esp32
idf.py build

The hardware config enables WiFi, BLE, PSRAM, and the OTA partition table.

Flash via ESP32-CAM-MB

If using the carrier board with CH340G USB-to-serial:

idf.py -p /dev/ttyUSB0 flash monitor

The MB board handles the boot mode (GPIO0 pulled low) and reset automatically.

Flash via external USB-to-serial adapter

If using a bare ESP32-CAM without the MB board:

1. Connect the adapter:

   • Adapter TX → ESP32-CAM RX (GPIO3)
   • Adapter RX → ESP32-CAM TX (GPIO1)
   • Adapter GND → ESP32-CAM GND
   • 5V → ESP32-CAM 5V

2. Enter flash mode:

   • Connect GPIO0 to GND
   • Press the RST button (or cycle power)
   • GPIO0 can be released after boot

3. Flash:

   idf.py -p /dev/ttyUSB0 flash

4. Run (normal mode):

   • Disconnect GPIO0 from GND
   • Press RST again

Connecting the LoRa module

After flashing, connect the RYLR module to the ESP32-CAM:

ESP32-CAM Pin	RYLR Pin	Function
GPIO1 (TX)	RXD	ESP32 transmits to module
GPIO3 (RX)	TXD	Module transmits to ESP32
3.3V	VDD	Power (RYLR runs at 3.3V)
GND	GND	Ground

Caution

The LoRa module must be disconnected when flashing via UART, since it shares GPIO 1/3 with the programming port. After initial flash, use OTA updates for field firmware changes.

Startup sequence

After power-on (normal mode, K1 not held):

1. Initialize NVS
2. Load LoRa config from NVS (or use defaults)
3. Check if WiFi is provisioned
4. If not provisioned → start BLE provisioning (use ESP SoftAP Provisioning app)
5. Connect to WiFi
6. Start remote syslog logging
7. Initialize RYLR LoRa module via AT commands
8. Start camera-to-LoRa pipeline task

Serial monitor

If the LoRa module is not yet connected, you can still use the serial console:

idf.py -p /dev/ttyUSB0 monitor

Press Ctrl+] to exit the monitor.

Note

Once the LoRa module is connected to GPIO 1/3, serial monitor output will be LoRa AT traffic, not readable logs. Use remote syslog (UDP) for log access in production.