Thomas Trummer - 2018-06-02

Hello,

I'm trying to use my raspberry pi 3 with stretch as a bluetooth hfp device.
So far so good. I'm using bluealsa, aplay and arecord but it is not possible for me to get bidirectional communication

If I call "arecord -c 1 -r 8000 -D bluealsa:HCI=hci0,DEV=88:83:22:EE:D2:0E,PROFILE=sco | aplay" I get some voice on my speakers
If I call "arecord -c 1 -r 8000 | aplay -D bluealsa:HCI=hci0,DEV=88:83:22:EE:D2:0E,PROFILE=sco" the opposite can hear my voice from my microphone
But if I call both at the same time within 2 command prompts only one of the commands or none of them works.

I also tried to call "arecord -c 1 -r 8000 -D bluealsa:HCI=hci0,DEV=88:83:22:EE:D2:0E,PROFILE=sco sco.wav" and "aplay -D bluealsa:HCI=hci0,DEV=88:83:22:EE:D2:0E,PROFILE=sco test.wav" at the same time and this works.
So if I use a wav file instead of the audio input (microphone) and record the other direction to a file instead of route it to the speaker everthing works fine.

Also if I try to call "arecord | aplay" noting comes out of the speakers.
If I call "arecord test.wav" and after some seconds "aplay test.wav" I hear the recorded sound.

I use an external sound card called "audio injector octo". Maybe this ies relevant.

Please give me a hint to solve my problem.

Thanks
Thomas

 

Last edit: Thomas Trummer 2018-06-02