My application is a HFP connected to a AG.
When the AG discover the HFP and they echange the pin code, it's ok. ( SDP record for HFP, ok)
But when the HFP send AT the AG respond ERROR to all the command.
If i change the rfcomm_port, sometime there's no reponse or another ERROR.
Example on port number 3, the phone accepte the HFP. If i send an external call from the phone the communication use the HFP. if i receive an external call the RING string is send to the HFP, and the commande AT+CKPD=200, is executed, the communication use the HFP.
Now, if i send any commande for a call ( ATDT..., ATDL, AT+BLND ...) i have the message ERROR.
Can you help me ?