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Problem with playing WAV on uVGA-II_GFX2

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  • Problem with playing WAV on uVGA-II_GFX2

    I am not able to get a wav-file out of the speaker.
    Using the amplifier LM386N right out of the datasheet from the Picaso, i hear only a permanent low frequent tone from the moment the wav-file should play until powerdown the modul..
    i tryed different wav tones with different resolutions.

    Regards,
    Frank

    PS: I tested my different wav-files also with the FAT-Controller with SGC-firmware. There is also no audio output. Has everyone a working wav-file like the Windows "ding.wav"?
    PS_2: I load the PmmC 2.4, which produce no permanent tone instead the wav-file.

  • #2


    Sound like the wav files aren't the correct format.

    What does this demo/checker have to say about them?

    http://www.4dsystems.com.au/code/index.php?node=77&id=85
    Mark

    Comment


    • #3


      I run the WaveDemo.4DG.
      But i have no Touchscreen, only a standard VGA monitor.

      The code beyond works, but it is very difficult to hear, because it is very quiet.
      I suggest, that my 50Ohm mini-speaker is too small and the resistant is to high.

      #platform "uVGA-II_GFX2"
      #inherit "PicasoGFX2_Functions.fnc"
      func main()
      var hFile;
      pause(5000);
      file_Mount();

      snd_Volume(127);
      repeat
      file_PlayWAV("ding1.wav");
      pause(300);
      forever
      endfunc

      Regards,
      Frank

      Comment


      • #4


        Ahh, you might like to marry the WaveDemo program with the mouse demo

        Yeah, the amp is not very loud anyway and a 50ohm speaker will make it even quieter
        Mark

        Comment


        • #5


          When the sounds ended, there is a high frequent tone stay permanent.

          snd_Volume(127);
          file_PlayWAV("ding1.wav");
          pause(300);
          snd_Volume(10);

          When i reduce the Volume after playing wav like above, then there is a click noise.

          Regards,
          Frank

          Comment


          • #6


            From one of the manuals "The ideal sample rate of the WAV file is 16Khz-Mono and the maximum should be 22Khz. Any higher sample rate will extremely slow down the system. Sample rates below 12Khz, the PWM will cause aliasing (filtering is a bare minimum). If you only hear noise or random snippets of sound remember, the Speed and Capacity of the memory card are important, most 2Gb cards should be fine, 64mb cards fail all but the most simple sounds."

            That will give you a few 'hints'. The other relevant bits are that the PWM is left running after the sound finishes. This is to stop the audible click that occurs when the PWM is stopped, which is what happens when the volume is 'completely', lowered.

            So the trick is to make the PWM so high that it's inaudible (unless you want to filter it out)
            Mark

            Comment

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