@ofauchon, I’m comparing my code with an existing library, “pyLora” and “raspi-lora” and for the moment i’m able to transmit a message from my raspberry pi (that uses lora bee “sx1276”) to a lora-ttgo board. the problem i’m facing now it’s about the range, i mean i’m using the same Tx power for both examples (example uses raspi-lora library after correcting it to use the lora mode and in the other example i’m using my library) and when i use my library i need to get both boards closer to be able to catch the data which is weird because i’m almost sure we have the same function that writes the output power and maxpower to the SX1276 register. i will upload the code to github soon and i will send you the link so you can have a look. and about your suggestion it will be a pleasure for me to have more information how things suppose to be done. thank you.