===== Communication Test =====

To test the connection between Raspberry Pi and Carberry board, from minicom, send the command:

  AT<CR><LF>

Carberry will replyes with 

  OK<CR><LF>

Indicating succesfully connection.

==== Notes ====

  - Every command line must be terminated by the two characters <CR> and <LF>, respectively in HEX 0x0D and 0x0A.
  - Every line returned from Carberry, is terminated by the two characters <CR> and <LF>.
  - After successfully execution of the command, Carberry returns possible line of replies, and than finish the sentence with "OK".
  - In case of errors, Carberry issues the keyword "ERROR", followed by the reason of that.