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stm32f769i-DISCO audio line in

Beaulier.Francois
Associate II
Posted on November 20, 2016 at 14:50

Hi,

I'am trying to get the audio from WM8994 line input.

The BSP driver seems rather incomplete, it works with the 4 mems mics but not with the line input from the codec.

Is there somewhere any source code example for that ? anyone facing the same problem ?

I can share some code that tries to do playback from line in to headphone out if someone interested.

Regards

Francois 

#stm32f769i-disco-audio-wm8994
16 REPLIES 16
Posted on April 05, 2017 at 01:36

when you say 'noisy' do you mean line noise? like static or something?

Posted on May 27, 2017 at 14:21

It actually sounds nice if you back off on the input signal strength. it is after all, line level in not speaker in.

john doe
Lead
Posted on May 28, 2017 at 23:33

Thank you

Beaulier.Francois

https://github.com/ProjectsByJRP/audio_pass-through

Posted on March 25, 2018 at 07:36

thanks a lot for posting this code john. did you run into issues with noise on the codec's line in? I get enough noise to make the board unusable for audio processing with the code you posted, and with ST's audio loopback demo (which may be new.) I tried powering the board from an external linear Psu as well. gonna have a look at the hefty datasheet of the WM8994 to see if I can reduce the noise by changing some analog path settings or something.

Adam L.
Associate

I had a similar problem on my STM32F723E-disco board. Noise level on line-in input was unacceptable. Problem lied in wrong connection between PC and board. Supplying power from phone charger solved this issue. More can be found here: https://forum.cockos.com/showthread.php?t=113721

its very great example... thank.. but i want 8K audio frequency & it not working... it working just >= 16K audio frequency... can u tell me why? because i want slow speed DSP audio

I am also facing same problem to get analog audio signal from line in jack at stm32f769i discovery board.

If you have this code,Please share whole working zipped project file.