RAK4630 : SX1262 Reset


I’ve hard time with SX1262 reset line from nrf52840 :


I’ve the exact same code as SX126x-Arduino library (copied from) and when I use the following initialization :

pinMode(_hwConfig.PIN_LORA_RESET, OUTPUT);
digitalWrite(_hwConfig.PIN_LORA_RESET, HIGH);

I can’t access anymore to the SX1262.
If I remove pinMode, I can read and get the correct value from REG_LR_SYNCWORD for exemple.

The difference is that this code is embedded in another one, but this code do not use this pin. I’ve tried the HAL provided with this other code, and get the same behavior (the code is almost identical).

Do I missed something ?
Is there any initialization in the Arduino bootloader that I missed ?

BTW, where can I find the RAK463x Arduino bootloader code ?


Hi Vincent,

What exactly are you trying to do?

Why do you use a “copy” of the SX126x-Arduino library and not the library itself?

The initialization of the SX1262 has nothing to do with the bootloader.

The bootloader source code can be found here: RAK4630 Bootloader

Thanks for the answer @beegee,

The problem was the GPIO output voltage.
It was set on 1.8V, which sound to be enough for SPI (I don’t know the spec) but not for the reset line. With 1.8V it was seen as SET and obviously I was not able to communicate.

It was hard to find with no means to probe the RAK4631 inside GPIO :frowning:

BTW, it’s specified in bootloader :

// change default 1.8v to 3.3v, add by taylor