Reading values from audio input pins using analogRead?

Software Development
1

Hello, as per title, I’m trying to read values from the audio input pins just like any other analog pins.
Is that doable?
I’m using DaisyDuino, so I’m using readAnalog(?) but have no idea how to access that pin.

EDIT: further clarification, I’m trying to read a potentiometer attached to one of the audio input pins. The behaviour is so weird to me, I can hear the noise if I pipe in[0] into out[0], the potentiometer is definitely doing it’s job. But if I try and average the input values coming into the audio callback, the value is basically just noise with occasional spikes when I twist the potentiometer.

Thanks!

2

The audio inputs and outputs are capacitor-coupled, so they’ll only pass AC.
Additionally, audio in and out are handled by an external codec, so they’re not accessible with analogRead or analogWrite.
There are other pins that are appropriate for reading pots.

3

thanks for the reply, I eventually managed to get potentiometer values despite the AC and codec.
There are indeed the ADC pins for this kind of job and this is a last resort for who desperately needs extra ADC values.
The solution involves summing abs(in[channel][iter]) while in the audio callback, then filtering out the spikes that will happen when the potentiometer is rotated.
if(accumulatedValue < threshold) inputAsPot = accumulatedValue;
I can now get a fairly accurate values from the input channels, if not a bit wobbly at time, but for my use case it works well.

4

Interesting - does this method return a useful value even if the pot is never moved?

5

yes, leaving the pot alone will return a nice stable-ish value, I do accumulate that though and average every X iterations, to clean it even further.
The pot is just connected to the board’s cv and the two grounds, but apparently that’s enough to pass the audio filter, in fact I can actually hear the buzz if I pipe in to out.
One trick is to amplify the audio in[] value at every iteration when accumulating, to maximise precision:

void audioUpdate(float **in, float **out, size_t size) {
	float inAudio1 = 0.0;
	for (size_t i = 0; i < size; i++) {
		inAudio1 += abs(in[1][i]) * 1024;
	}

	if(inAudio1 < threshold){
		myPotValue = inAudio1 / arbitraryRangeValue;
	}
}