by bengchet » Thu May 03, 2018 2:56 pm
Hi,
It is using UART Interface. So just input exactly the command using UART.
If you are using Arduino, it is like
Serial.println("radio set mod fsk");
But I would suggest you try other commands before trying this, such as "sys get ver", "sys reset", etc to make sure you can communicate with the module. Check page 12 of the document for UART Interface settings.