Heltec WiFi LoRa 32 V3
Compact LoRa node with OLED display, battery ADC, and USB-C. ESP32-S3 with SX1262 radio.
Overview
| MCU | ESP32-S3 (dual-core Xtensa LX7, 240 MHz) |
| Flash | 8 MB |
| PSRAM | 8 MB |
| Connectivity | WiFi 4 + BLE 5.0 (on-chip), USB-C |
| Status | Supported |
Components
| Component | Chip | Interface | Driver | Status |
|---|---|---|---|---|
| OLED display | SSD1306 128×64 | I2C 0x3C (SDA=17, SCL=18, RST=21) | drv_oled_ssd1306 | Proven |
| LoRa radio | SX1262 | SPI (CS=8, RST=12, BUSY=13, DIO1=14, TCXO=true) | drv_radio_sx1262 (C/RadioLib) | Proven |
| Battery ADC | ADC on GPIO 1 | ADC | drv_power_tp4065b | Untested |
Pin assignments
| Function | GPIO |
|---|---|
| OLED SDA | 17 |
| OLED SCL | 18 |
| OLED RST | 21 |
| Vext power | 36 (drive LOW to enable) |
| LoRa CS | 8 |
| LoRa RST | 12 |
| LoRa BUSY | 13 |
| LoRa DIO1 | 14 |
| Battery ADC | 1 |
Board config
Config file: heltec-v3.json
Located at sdcard_layout/config/boards/heltec-v3.json in the source tree.
Notes
- Vext power on GPIO 36 must be driven LOW to enable peripheral power (OLED, etc.). This is handled by the
pin_vextconfig in the board JSON. - LoRa SX1262 uses TCXO (temperature-compensated crystal oscillator).
- Battery ADC driver is untested on this board.
- Good for: LoRa mesh node, compact sensor hub.