Sound capture

  • Hello,


    i have a picocom3 starter kit and i want to play and capture audio with the alsa library.
    The playback works fine, but the capture does not work. I have tried the format 8 bit and 16 bit format at a sample rate of 16kHz but the only thing i hear is "clicking".
    The same problem occurs with arecord.
    The capture switch is set to "Line".
    I noticed switching the "Capture Input" while capturing audio that the clicking disappears for a short time.


    Is there somthing else to do beside setting the Capture switch? I hope this is not a bug.

  • I tried arecord too to capture audio and I can confirm this behaviour.
    I even grounded both LIN and RIN but when I look through wav file recorded I can see that one channel is ok (zero samples) while the second channel is full of 1-sample-length peaks. Their amplitude is always to maximum, some are positive, some negative. Distance between peaks is variable, but seems to be approx 3,7ms or multiple of this value (typically 7,5ms or 11,5ms).

  • Yes, the sound capture problem is a known problem. Even if you don't see it yet, but we are working on a completely new release of the PicoMOD6 and PicoCOM3 Linux software, based on rather up-to-date versions of U-Boot, Kernel and BuildRoot. There the audio support will be much better. Don't expect a release before end of August, but we are working on it.

    F&S Elektronik Systeme GmbH
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    Da dies ein internationales Forum ist, bitten wir darum, Beiträge möglichst in Englisch zu verfassen.