The RF-LORA-868 is an easily available SX1272 LoRa implementation and readily connected via the PI4 GPIO connector. The PI4 SPI driver provides the active link with two additional pins for Reset and TX/RX control. This particular application is as a hub for my LoRaLan implementation.
The code is mostly derived from Heltec Aduino interface for the SX1276. There are minor config register differences between SX1272 and SX1276 hence the #define SX1272. Of note is that the SX1272 minimum signal bandwith is 125Khz. The SX1276 chips must be set to the same bandwidth.
My interface difers from the Heltec implementation in using a non-blocking continuous receive implementation.
Make files are provided to build the LoRa + SPI library and the LoRaReceiver and LoRaSender demonstrations. If the inital register dump gives you zeros you have a problem with the SPI connection.
| GPIO | RF-LORA-68 | Function |
|---|---|---|
| 10 | 15 | MOSI |
| 09 | 14 | MISO |
| 11 | 13 | SCCK |
| 08 | 16 | /CEO |
| 23 | 4 | TX/RX |
| 24 | 12 | Reset |
| Pin 17 | 5 + 3 | Vcc(3v3) |
| Pin 20 | 2 | Gnd |
ChiefEngineer