At a guess, the two transducers are not adequately decoupled with respect to the power supply and I'm guessing the potentiometer is a fairly low resistance and the pressure sensor has a high resistance so that their respective current flow changes are very different.
Solutions could be to either
- Change the power supply to something that can source a higher
flow - is it a USB powered thing?
- Put a big (33,000uF or 68,000uF) capacitors across each sensors
supply close to it.
On Thu, 12 Nov 2009 18:02:05 +0100 altern altern2@gmail.com wrote:
hi
not a PD question I guess... i dont know much of electrical stuff. i am connecting two analog sensors to the arduino. One is a pressure sensor and the second a potentiometer, they are both from an old icube.
i noticed that when i raise the potentiometer (analog pin 5) the pressure sensor (analog pin 2) reports values ranging 0 to ~0.16 increasing together as the potenciometer goes up. It is like some kind of residual noise comming from pin 5 that goes into pin 0.
the power cables of both sensors go together to 5v inlet of the arduino and the ground cables go to ground pin, each of the data cable goes to its separate analog pin.
I am using arduino from Pure Data extended using latest Firmata, so i am just filtering out any value smaller than 0.16 coming from analog pin 0.
is there anything I am doing wrong? or is this normal?
thanks
enrike
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