I have two devices connected via Bluetooth. Currently I am to initiate voice call from my device (programmatically from my app) to another device, after connecting to it using Handsfree Audio Gateway.
However, I am only able to initiate the call and not hear the other end or send my voice once the call is established. I realize that there is something more I must do for this. But I am unable to find out what it is. Perhaps there is an AT command for initiating call and routing audio to the Bluetooth connected handset? Or any other way?
My coding attempts so far are described here in this question : How to initiate a call from HF through AG via Handfree Audio Gateway in Android?
There is no AT command to start a SCO link (Audio link) over BT.
A SCO link is started in Android by using AudioManager.startBluetoothSco()
Have not used this myself so I can't help you more about this.
Have you really connect a Bluetooth HF connection between two Android phones? I tought they only supported AG role not HF. It isn't a SPP connection you are using?