SIM900 Voice call help

[milan.rajik]

I want to know how to make a voice call using SIM900. I have connected audio out of APR33A3-C2 to MIC IN of SIM900. I will be playing messages stored in APR33A3-C2. I know how to dial a number using micro and SIM900. What I want to know is how to know that the receiver has picked up the call so that I can start playing the voice messages. Does SIM900 give any response when call made is received at the other end? If not, then how to know that that the call is received or not?

 

[ponnus]

Hai,
In SIM900 datasheet v1_06, it states that,

For voice call, two different responses can be determined. TA returns "OK" immediately either after dialing was completed or after the call is established. The setting is controlled by AT+COLP. Factory default is AT+COLP=0, this cause the TA returns "OK" immediately after dialing was completed.

Also,

The current states of all calls can be easily checked at any time by using the AT+CLCC command

Hope this helps,