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Use of the Demo board's mic — Parallax Forums

Use of the Demo board's mic

Thomas FletcherThomas Fletcher Posts: 91
edited 2009-09-28 09:17 in Propeller 1
I was wondering if anybody has written a spin program using the demo board's microphone. There is one assembly program in the exchange but
I am looking for something simple for this simple mind. I would like to get a numerical value (freq or volume) that
I could use to manipulate led patterns.

Comments

  • StefanL38StefanL38 Posts: 2,292
    edited 2009-09-27 14:05
    Hello Thomas,

    the solution depends on what you want.

    For getting a volume-value you can use the ADC-object from the ANN1 (Application-Note 1 using the counters
    See attached zip-archive. This archive contains a file ADC.SPIN

    The shematic Propeller Demo Board Rev D/E/F Schematic (11-29-06) shows the mic connected to PIN 8 and 9

    You have to change the PIN-assignments.
      fbpin = 9
      adcpin = 8
    
    



    This object starts a cog and reads in the ADC-value to variable "value"

    Once the value is read in you can do whatever you like with it

    best regards

    Stefan
  • Thomas FletcherThomas Fletcher Posts: 91
    edited 2009-09-28 00:06
    Thanks. That got it going for me. Short video.

    www.facebook.com/video/video.php?v=172090980549
  • VIRANDVIRAND Posts: 656
    edited 2009-09-28 09:17
    I am lately working on that, recently posted some noisy experiments "Miscellaneous Sound Demos".
    Currently fooling with mic-to-headphones OB as ADC, and bitbang PWM as DAC,
    for sound and voice changing effects.
    I think I have something almost ready with 8-bit sound in and out for an effect BUT
    I'm using pin 7 as sound output because 10 and 11 are used up,
    and it gets noisier if I try to patch in to the headphones, maybe they're part of a feedback loop.

    Mic to VGA O-scope OB was harder to modify for mic use but maybe better for my purpose to try it again.
    Part of the problem was cog <-> hub communication and inconsistent seeming effects of using @ symbols.

    The microphone is not connected the way I would rather use it, so it's strange to me.
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