swaits
a1b92356b3
First classic-ESP32 (non-S3) board in the firmware, and first SX127x radio. ESP32 + SX1276 + SSD1306 OLED + AXP192 PMIC, CP2102 USB-UART bridge. Pin map verified from MeshCore variants/lilygo_tbeam_SX1276. The AXP192 gates power to the LoRa chip and OLED. Its I²C bus is shared with the display, so the firmware builds I²C0 in blocking mode first for the PMIC init, then converts the same handle to async and hands it to the display task — avoids double-consuming the peripheral. Lora-phy's Sx127x support drives DIO0 as the sole IRQ (SX127x has no BUSY line); the chip runs from a crystal, tx_boost routes +20 dBm through PA_BOOST. The `esp-hal` / `esp-rtos` / `esp-backtrace` / `esp-println` deps have been restructured so the chip flavour (esp32 vs esp32s3) is selected at the per-board feature level instead of baked into the dep lines. This keeps the existing S3 boards building on esp32s3 while the new T-Beam feature selects classic esp32 via the same dependency set. LoRaBoard gains supported_sf_bitmap() / supported_bw_bitmap() methods (with SX126x defaults) so the T-Beam can report SF6–SF12 via GET_INFO — the SX1276 has no SF5. radio_chip_id() reports 0x0011 per donglora-protocol RadioChipId::Sx1276. freq_range_hz widens to the SX1276 datasheet span of 137 MHz–1020 MHz. New modules: - src/hal/esp32.rs — classic-ESP32 MCU primitives - src/board/esp32.rs — Sx127x radio + SSD1306 display pipe - src/board/lilygo_tbeam.rs — the board file - src/driver/axp.rs — AXP192 init added alongside AXP2101
2.5 KiB
DongLoRa Firmware
Embedded Rust firmware for DongLoRa boards. Exposes the LoRa radio over USB CDC-ACM using a COBS-framed binary protocol.
Building
just setup # one-time toolchain install
just build heltec_v4 # build for a specific board
just flash heltec_v4 # build + flash
just check-all # compile-check all boards
just clippy heltec_v4 # lint
just test # host-side protocol unit tests
All commands are run from the firmware/ directory.
Supported Boards
| Board | Feature | MCU | Radio | USB | Target |
|---|---|---|---|---|---|
| Heltec V3 | heltec_v3 |
ESP32-S3 | SX1262 | Native CDC-ACM | xtensa-esp32s3-none-elf |
| Heltec V3 (UART) | heltec_v3_uart |
ESP32-S3 | SX1262 | CP2102 bridge | xtensa-esp32s3-none-elf |
| Heltec V4 | heltec_v4 |
ESP32-S3 | SX1262 | Native CDC-ACM | xtensa-esp32s3-none-elf |
| ELECROW ThinkNode-M2 | elecrow_thinknode_m2 |
ESP32-S3 | SX1262 | CP2102 bridge | xtensa-esp32s3-none-elf |
| LilyGo T-Beam | lilygo_tbeam |
ESP32 | SX1276 | CP2102 bridge | xtensa-esp32-none-elf |
| LilyGo T-Beam S3 Supreme | lilygo_tbeam_supreme |
ESP32-S3 | SX1262 | Native CDC-ACM | xtensa-esp32s3-none-elf |
| RAK WisBlock 4631 | rak_wisblock_4631 |
nRF52840 | SX1262 | Native CDC-ACM | thumbv7em-none-eabihf |
| Waveshare RP2040-LoRa | waveshare_rp2040_lora |
RP2040 | SX1262 | Native CDC-ACM | thumbv6m-none-eabi |
| Wio Tracker L1 | wio_tracker_l1 |
nRF52840 | SX1262 | Native CDC-ACM | thumbv7em-none-eabihf |
Heltec V3 USB Note
The default heltec_v3 build uses native USB CDC-ACM, which requires a
hardware modification to your board. Stock Heltec V3 boards route USB through a
CP2102 bridge chip to UART — the ESP32-S3's native USB pins (GPIO19/GPIO20) are
routed to header pins but not connected to the USB connector.
To enable native USB on a Heltec V3:
- Solder 0-ohm (or 22-ohm) resistors at pads R29 (D+) and R3 (D-)
- Disconnect the CP2102 from the USB connector's D+/D- lines (cut traces or remove the CP2102 bridge resistors)
After this mod, the board appears as /dev/ttyACM0 with the DongLoRa VID:PID
(1209:5741), just like the V4 and nRF boards.
If you have a stock (unmodified) V3, use heltec_v3_uart instead:
just build heltec_v3_uart
just flash heltec_v3_uart
This builds firmware that communicates via the CP2102 bridge (appears as
/dev/ttyUSB0).
Adding a Board
See src/board/PORTING.md.
Protocol
See PROTOCOL.md for the complete wire format specification.