I have a stereo VU meter. (Audio in on Arduino pins A0 and A1 and GND to common GND also 32ohm resistors going to GND on A0 and A1 to simulate coming speakers)
Now my problem is software architecture makes each channel very sensitive to voltage changes (adapting to lower volume on each volume separately) so in turn when there is only single channel input I get fluctuations (about the same) on each channel. So, how do I isolate the two analog inputs on Arduino?
Edit: software proves, if AREF if 5V then we are measuring about 0.01V for one step on a ten step VU meter. That's why I blame very fine voltage changes in overall Vin to GND voltage for this effect I'm seeing.
schematic http://i.imgup.hu/3OqfH5.png
If I remove the 32ohm resistors going to GND, nothing changes. Should I provide Arduino code?