These pin assignments are defined in firmware/node/include/config.h and match the Heltec WiFi LoRa 32 V3 board’s internal wiring. You should not need to change these unless you are using a different board.
| Constant | GPIO | Function |
|---|
LORA_NSS | 8 | SPI chip-select for the SX1262 |
LORA_DIO1 | 14 | SX1262 interrupt pin (signals packet received) |
LORA_RST | 12 | SX1262 hardware reset |
LORA_BUSY | 13 | SX1262 busy signal (indicates chip is processing) |
LORA_SCK | 9 | SPI clock |
LORA_MISO | 11 | SPI data in (master in, slave out) |
LORA_MOSI | 10 | SPI data out (master out, slave in) |
| Constant | GPIO | Function |
|---|
OLED_SDA | 17 | I2C data line (shared by OLED, TMP102, and BMP280) |
OLED_SCL | 18 | I2C clock line (shared by OLED, TMP102, and BMP280) |
OLED_RST | 21 | OLED display hardware reset |
| Constant | GPIO | Function |
|---|
PIN_VEXT | 36 | Peripheral power enable (active LOW — drive LOW to turn on 3.3V rail) |
PIN_LED | 35 | Onboard LED |
These are not GPIO pins but are configured alongside the pin definitions:
| Device | Default Address | Alternate Address | Set By |
|---|
| SSD1306 OLED | 0x3C | — | Fixed on board |
| TMP102 | 0x48 | 0x49 | ADD0 pin (GND = 0x48, VCC = 0x49) |
| BMP280 | 0x76 | 0x77 | SDO pin (GND = 0x76, VCC = 0x77) |
