Inconsistency in SX1280 SPI Read Functions: Required Buffer Adjustment

[sluissantos]

Here’s an improved version of your text:

I am working on a project using LoRa 2.4GHz, and here are the details of my setup:

Development Environment: SES 8.18, nRF5 SDK Version 17.1, nRF52832
Transceiver: E28-2G4M12S (SX1280)
Gateway: MikroTik wAP LR2 kit
I am adapting the example from application_example/2_porting_nrf_52840 to work with the nRF52832.

After spending a significant amount of time reviewing the stack commands, I discovered an inconsistency.

The default sx128x_hal appear to have an issue with the SPI read data functions in this setup. To read data correctly, the rx buffer must include the tx command length over SPI.

For instance, using the default stack's ReadRegister command:

The rx buffer needs to be shifted by 4 bytes, meaning the correct return is offset by 4 positions. Therefore, it is necessary to increase the rx buffer length by 4 bytes (3 for the command and 1 for the NOP).

The returned status bytes are almost always: 0x45, 0x47, 0x47, ...

This adjustment is required for all instructions that involve retrieving data from the radio.

Additionally, when using the wAP LR2 Kit, I had to update the firmware to the latest version.

With these changes, my application is now working perfectly.