I've got a Bluetooth device that has a ten-pin mini-USB output port (a Sena GP10 GoPro bluetooth audio receiver). Two of those pins output a mic-level microphone signal, but I don't know which ones. I want to figure out a way to adapt the mini-USB output port into a standard microphone TRS connector so I can plug the receiver directly into an audio recorder.
Unfortunately I don't have an oscilloscope, only a standard multimeter, so for any kind of analog audio cable the DMM gives me a reading of 0V since it averages out the positive and negative AC voltage readings.
I don't want to just blindly connect random combinations of pins into an audio recording device because I'm not sure what all the other pins do and I don't want to risk perhaps blowing the audio recorder.