i need help to connect audio output to adc

Alec_t

Joined Sep 17, 2013
12,320
The ADC input will need to be DC-biased to about half the Arduino's supply voltage (assumed to be 5V), so that negative peaks of the audio signal don't drive the ADC input negative.
If the post #22 circuit is your radio tuner (albeit not a very good one), then you could ignore the 220n capacitor, connect the ADC input directly to the Q3 collector and connect a 10k resistor from Q3 collector to ground. The ADC input will thus be kept in the 0-4.5V range.
Incidentally, I think 560k is too low a value for the Q3 base bias resistor, unless Q3 has a very low current gain.
 
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Thread Starter

michael1978

Joined Jun 29, 2014
309
The ADC input will need to be DC-biased to about half the Arduino's supply voltage (assumed to be 5V), so that negative peaks of the audio signal don't drive the ADC input negative.
If the post #22 circuit is your radio tuner (albeit not a very good one), then you could ignore the 220n capacitor, connect the ADC input directly to the Q3 collector and connect a 10k resistor from Q3 collector to ground. The ADC input will thus be kept in the 0-4.5V range.
Incidentally, I think 560k is too low a value for the Q3 base bias resistor, unless Q3 has a very low current gain.
Thank you ver much
 
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