ESP32 LoRa APRS Modem

This project is amateur radio ESP32 based LoRa/FSK KISS Bluetooth/BLE/USB/TCPIP modem + LoRa APRS-IS RX/TX iGate server over WiFI + LoRa/FSK APRS digipeater + Codec2 DV modem (with Codec2 Talkie Android application).

⚠ To configure sketch modify default parameters in config.h file or board specific pinouts in variants/[board]/variant.h.

• For project description, detailed setup and more information, please, visit our Wiki at https://github.com/sh123/esp32_loraprs/wiki
• For discussions, visit https://github.com/sh123/esp32_loraprs/discussions

⚠ Project also supports APRSDroid TNC2 text APRS packet mode (configurable), which makes it interoperable with other LoRa APRS trackers without AX25 support.

Supported module types: SX126X, SX127X and other modules supported by RadioLib, idle RX power consumption is around 60mA, so single 18650 cell should last for about 24 hours in RX.

Modules, which are used by users and known to work

• SX126X (suggested, 1W/2W modules will provide decent coverage for APRS, stable frequency suitable for < 125 kHz BW at 433 MHz, 5V from USB power bank is enough to power it, has additional LNA)
  • 👍 E22-400M30S/E22-400M33S (SX1268)
  • E220-400M30S (LLCC68) BW125 SF from 7 to 9 (chip limitations)
  • These modules are 30dbm modules, but maximum power should be set to no more than 20-22dbm, see https://github.com/jgromes/RadioLib/wiki/High-power-Radio-Modules-Guide
• SX127X (low power, 50-100mW, temperature frequency drift, problematic for narrow band)
  • RA-01 (SX1278)
  • RA-02 (SX1276)
  • TTGO T-Beam (SX1276)

Building

• Update include/config.h with your radio settings
  • If you are using lora-aprs iGate (non AX.25) then set CFG_TEXT_PACKETS and CFG_TEXT_PACKETS_3 config parameters to true and use APRSDroid TNC2 connection protocol
• To build for client/tracker mode use pio run -e esp32dev_e22_modem
• To build for iGate mode use pio run -e esp32dev_e22_igate

Development board

Development board schematics, case and antenna models are available under extras/cad and extras/schematics.

Supported ESP32 boards are with 36 and 38 pinouts (configured with solder pads) and ESP32-C3 with separate board.

⚠ There are ESP32 boards with different socket widths: 22mm and 25mm, board files for 25mm have _wide suffix in file names.