Society of Robots - Robot Forum
Electronics => Electronics => Topic started by: 555 timer chip guy on March 20, 2007, 05:40:01 PM
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Dos any one have a circuit that can recognize a specific frequency.
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do a google search for a notch filter or bandpass filter.
you can use an op amp or a simple RLC circuit.
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the G8870 decodes DTMF Freqs.
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It needs to be able to recognize square wave forms.
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maybe a DAC before the notch filter. Or use a cap in parallel with the receiver to convert to sinusoidal. I don't know of any offhand but they make tone decoder IC's which also might work
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why don't you ADC your signal, and then filter in software? (e.g., use DSP). Much easier to find a square wave.
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thanks but I don't know how to do that yet. :(
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You will need to play with the values a lot but here is a basic circuit that should work.
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You will need to play with the values a lot but here is a basic circuit that should work.
Thanks for that schematic I was looking at some thing very similar a littel wile ago
do you haze any basic starting values I could use for maybe 100Hz , and also I heard you could use a comparator and a crystal to recognize a frequency.
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<-noob
Isn't that what an osciliascope is for?
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well, if you don't have an extra $160 laying around for an oscillosope, you could use the "inductor in series with an LED brightness test" or the "speaker and function generator guesstimation".