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Phase of in incoming signal — Parallax Forums

Phase of in incoming signal

EricEric Posts: 11
edited 2009-03-26 16:16 in Propeller 1
I was looking at SN96's post under completed projects about "My Stamp Audio Sensor" and wanted to take this a little further.

I was wondering if the propeller can determine the phase difference of a signal coming in from different pins. For instance if I was feeding in two different signals (both sine waves) into two different pins and the phase was different by say 80 millisecs. Is there a way to calculate that?

I want to experiment with detecting sounds and determining the timing difference between two microphones in order determine direction.

Thanks for any help you may offer.

Eric

Post Edited (Eric) : 3/26/2009 2:59:57 PM GMT

Comments

  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2009-03-26 15:42
    Are you sure you meant 80ms as an example? That would entail a sine wave of less than 12.5Hz. Otherwise, it would not be possible to to detect a phase difference greater than one cycle, unless the incoming waves were more complex with distinguisable features at that scale.

    -Phil
  • EricEric Posts: 11
    edited 2009-03-26 16:16
    I'm sorry... 896 microseconds... If my math is right... If I initiate a sound and I have two microphones spaces 12" apart the maximum delay between them to hear the sound is 896 microsecs ( if my calculations are right at Sea level). Which would indicate that the sound is coming at a right angle to the microphones.. and the delay would be very minimal if at anything if the sound was ahead at 0 degrees.
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