I am using an arduino Uno with SIM800L, I am trying to send voice at anyway while a voice call is active, and how do I receive voice too?
I have searched a lot, but found nothing. Even though, I have reference which contains most of the AT commands that are applicable on my SIM800L. For example, when I make a voice call with my phone and the SIM800L, how do I receive the voice data from the GSM when I talk through my phone?
The GSM I have is SIM800L version 2, note that version 2 is different from version 1. However, it turned out that there are no at commands to send voice while a voice call is active, you must use another pin, not directly from the at commands. SIM800L has only 7 pins which is low, this is a picture of it : https://i.sstatic.net/d9LCE.jpg .
It does not have any pins for receiving and sending voice specialized for a voice call. So, you can answer a call and dial a number, but you can't hear or speak. So, all I can do is use another GSM that has the capability of receiving and sending voice.
However, if you would like to know if a GSM has the voice capability or not, you should find these couple of these pins or similar to them:
Search for SIM800C, which has these pins. You can also connect a basic speaker with an amplifier directly with the SPKN and SPKP, the amplifier is optional, but the sound will be too weak.
