Hello everyone,

I bought a module lonet SIM808 but I am a novice in programming with Arduino and for more than download libraries I can not make it work, could you tell me a some steps that I must follow to send AT commands and see if my module works.

I am using Arduino DUE and pins Tx and Rx 14 and 15 respectively.

Thank you very much in advance!

Try a simple echo test:

void setup()
  Serial.begin( 9600 );  // or whatever
  Serial3.begin( 9600 );

void loop()
  if (Serial3.available())
    Serial.write( );

  if (Serial.available())
    Serial3.write( );

Then you can type AT commands into the Serial Monitor window, and they will be sent out Serial3 (pins 14 & 15).

Likewise, the responses from Serial3 will be forwarded to Serial. Then you can see the responses on the Serial Monitor window.