Routing Audio from Aux In to USB dongle

[trick420]

Hello,

I'm attempting to take audio in on the Aux-In input, and I need to send it to a USB dongle to go to a BT headset. I have tried ALSA Mixer and Jack, but have so far come up short. Right now all I'm able to to is take audio in the Aux input and push it back out the Aux output after enabling output mixer line bypass in the audio device settings dialog. It seems like this should be fairly trivial. Am I missing something?

Running on an RPi 3 with the latest Raspbian. Any help is greatly appreciated.

Regards,
Jeff

[flatmax]

I think you want to do this but in reverse :
https://raspberrypi.stackexchange.com/q ... 6191#66191

What device numbers do you sound cards have in ALSA ?
Can you see them when you do aplay -l ?

say the Audio Injector card is device 1 and the USB dongle is device 0 :
arecord -D hw:1 | aplay -Dplug:dmix -

You use dmix on the output to try to resample the input as required to make sure when the clocks drift, there are no problems.

Matt