Multiple potentiometers

hi,

i'm building midi controller bunch of switches , potentiometers.
the switches working fine. installed 1 potentiometer and  - after quite bit of debugging - got work too.

the never resting geek in me told me install second potentiometer. causes problems, cause i'm getting crosstalk between 2 analog inputs. when change value a, (more or less) same value on b.

the potentiometer not installed on arduino board. use external expression pedal 20k pot connected arduino via jack inputs. (like wah wah pedal wit stereo jack - have connectors on controller , using 1 pedal far, unplugging , connecting second connector when wanted try second analog port)

here's code snippet i'm using debug

code: [select]


void exppedala(){
  int sensoravalue = analogread(a0);
serial.print("a: ");
serial.println(sensoravalue);
}

void exppedalb(){
  int sensorbvalue = analogread(a6); 
   serial.print("b: ");
serial.println(sensorbvalue);
}


when check output, can see both & b change values, although have 1 expression pedal connected. other jack input not connected anything.

i checked connections , think that's not problem:
pot cw goes arduino ground
pot ccw goes arduino a6
pot sl goes arduino 5.5 volts

i suspect problem 20k ohm expression pedal / pot providing. can't replace pot in expression pedal.

- getting crosstalk because potentiometer strong?
- if that's case: there way resolve without having replace potentiometer in expression pedal?

thanks help,

m.

try 2 analogue reads, discarding first.

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