first, i made the lora gateway and lora server with the rak2245 pi hat and dragino lora shield v1.4, and i used the arduino sketch in ( https://github.com/dragino/Lora/blob/master/Lora%20Shield/Examples/lora_shield_ttn/lora_shield_ttn.ino 1 ) and changed the keys and the device address to send data to the server and it works good using the json decoder in the following picture.
i also made a downlink from the server
but it gives me that i have null data as in the following picture
also when i send data from the MQTT on the Rpi by using the command
also the data recieved is null
and the data recieved on the node in not like the data i sent
where the data i send is a json file
when i use MQTT spy i can see the data coreectly arrived in the device.
so my problem is how to get the data sent from the mqtt on the node (see the data in the arduino serial) exactlly as it is?