@a.valero I don't really get you, as far as I understood using mac pause means that you do not use LoRaWan stack and mac resume means you do use LoRaWan stack (according to rn2483.pdf (362.3 KB) page 22)
Thus in briefly my tx should be something like below, if I send a FF ?
Serial1.write("mac pause ");
Serial1.write("radio tx FF");
being the receiver something like
Serial1.write("mac pause");
Serial1.write("radio set wdt 0");
Shouldn't I use the command radio rx 0 instead of the one that set the window?
Thank you very much