ADC

Custom PCB Boards Getting Started Tips Timing Pulse Generation Object Exchange FAQ Programming Examples

 

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One very interesting application for the Propeller is 1-bit Sigma-Delta ADC (analog to digital conversion).  This is made possible by the high clock speed.

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1-bit Sigma-Delta (ΣΔ) uses two Prop pins, one for input, one for output.  You also need two resistors and two capacitors (for DC coupled inputs). 

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Here's a typical setup:  

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For more info, be sure to read Parallax's "Counters" Appnote.

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Also, look at the Microphone2Vga demo .

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This applet can help pick resistor values.

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I've made an object and VGA demo that utilizes both counters of a cog to do simultaneous ΣΔ ADC of two inputs:

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Screenshots:    

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Download here.