This software emulates a KISS TNC and controls a hardware LoRa transceiver of 1st and 2nd generation (SX127x/SX126x) connected to the Raspberry´s SPI. That makes it possible to use existing APRS software, like aprx or direwolf, with LoRa radio communication, in order to build a powerful APRS digipeater with possibility to mix legacy FSK 1200bps with new Lora technology.
The software shall be executed together with the APRS digi APRX, which connects via "KISS over TCP" and provides powerful APRS digipeating and I-gate functionality for LoRa-APRS.
The Software keeps the compatibility with both standard AX25 packets and Austrian team packet style (called "OE_style").
The LoRa KISS TNC runs on Raspberry Pi 2 or newer together with the SX126x/SX127x LoRa Modules. 128x64 I2C Display (based os SSD1306chipset) is supported for showing last rx/tx packets. Can be enabled/disabled inside config.py
Theoretically, all LoRa modules using SX127x (RFM9x) or SX126x series (SX1261, SX1262, SX1268) or LLCC68 will compatible. However, I personally tested the following configuration:
- Raspberry Pi3
- Ebyte E22-400M30S Lora Module
- RFM96 Lora Module
Most useful and used parameters can be changed inside config.py. Specific section for sx127x/sx126x are present.
A Hat PCB has been developed by Michele I8FUC, however LoRa modules can be wired up to the Raspberry Pi directly aswell. See the schematic and the images images for further details. Note that the GPIO assignment in config.py refers to this schematic. Change it in case of custom assignment.
Power pins, SPI pins, RESET, IRQ pins must be connected between RPi and LoRa module in both sx126x/127x cases.
The default SPI port is using bus id 0 and cs id 0.
DIO1 must be connected for both sx127x/sx126x because is used as RX IRQ.
BUSY, TXEN and RXEN must be connected in case of SX126x Ebyte module because are used to manage the RX/TX switch of the module
Note: The GPIO pins are declared with Broadcom pin numbering, they does not indicate the position on the physical connector! To see the correspondance between them, see: https://pinout.xyz/
Read INSTALL.md for complete Software and Lora/display libraries installation guide
- Get buttons working
This software is an evolution of KISS TNC made by TOM OE9HTK for Lora 1st generation module: https://github.com/tomelec/RPi-LoRa-KISS-TNC Thanks TOM for nice work and starting idea
The PCB is designed by Michele I8FUC. Thanks Michele for nice design and support during Software testing.