Configuration commands

Check if PIN code is expected:

AT+CPIN?

Enter a PIN:

AT+CPIN=XXXX

Check status and configure hands-free:

AT+CHF?
AT+CHF=0,1

Get current phone number:

AT+CIMI

Make a call:

ATD+34666666666;

Mute:

AT+CMUT?

Commands to send a message

Set to text mode:

AT+CMGF=1

Enviar un mensaje (\n después del número):AT+CMGS="+34656333333"

MENSAJE 

Commands to configure calls

Incoming call sound:

AT+CRSL

Consultar el estado del volumen y subir el volumen al máximo (valores de 0 a 100):AT+CLVL?
AT+CLVL=100

Sonido de la alerta  (modo normal = 0, o silencio = 1):AT+CALM?

Control automatic audio switch.

  1. Disable the automatic audio channel switching function, the earphone HOOK function is disabled;
  2. Enable the automatic audio channel switching function, the earphone HOOK function is enabled;
  3. Disable the automatic audio channel switching function, the earphone HOOK function is enabled.
AT+CAAS

Switch audio channels (0=NORMAL_AUDIO, 1=AUX_AUDIO, 2=HANDFREE_AUDIO, 3=AUX_HANDFREE_AUDIO, 4=PCM_AUDIO):

AT+CHFA=1 

Dial tones in a call:

//Send DTMF tone #255*
AT+VTS="#,2,5,5,*"

Configure speaker monitor (loudness):

ATL3

Configure monitor speaker mode:

ATM3

Microphone usage

Echo cancellation:

AT+ECHO

Change the microphone gain:

AT+CMIC=<channel>,<gainlevel>

Switch audio channels

Official documentation.

Common startup issues: