Hi. I am using Colibri VF61 V1.2A and viola carrier board V1.2A with Linux as OS. I am successful in playing audio wav files using aplay. But I not able to record using mic which is 3.5 mm and is 3 conductor. Please help with exact connections to be made between mic connector and X10 connector on carrier board.
Does your 3.5mm 3 conductor connector has two seperate micro phones attached ? Dual micro phone support is not available on our platforms. Find the mic signal(mono) form your 3 conductor mic connector and connect the mic-in to X10-1 and gnd to X10-7. Also make sure the “Capture Select” is selected correctly in ALSA mixer. Refer this article for more info.
Note that neither the Colibri VF61 nor the Viola board have any biasing circuit.
So if you’re using a microphone which requires biasing you have to add it. Note that most headsets for handphones are of such a type.
You could reference the Colibri Evaluation Board which features a biasing circuit.
I did the same connections like connected mic-in to X10-1 and gnd to X10-7. But its still not working. I am using standard iball headphones.
I used following commands for recording :-
amixer set ‘Left Capture Select’ ‘Mic’
arecord -V mono -r 8000 -f S16_LE -c 1 Capture8kHz.wav
####### + | 38%
Here, in my case instead of 38%, its showing only 0-1%.
Did you checked for the mic biasing circuit as @max noted? Since the mic biasing circuit is not available on Viola carrier board one need to make sure to connect a mic with bias circuit or make sure the mic which is connected has biasing circuit.