I am building a controller to dim LEDs with very precise timing control, for a movie prop.
I just soldered the control board, using 6x 100k potentiometers as control knobs. But I feel like they are interfering with each other, as I am getting some strange results. At first, I thought I might have shorted something, but on second glance, I think it might be Ohm's Law creeping up on me...
The default positions for the pots are four at 0% (100k[ch937]) and two at 100% (0[ch937]). I tried doing ohm's law for this, but I got caught up with the two 0[ch937] pots, as that creates a division by zero problem; i.e. they might be shorting the whole +5v supply and messing up the other, high resistance pots.
My first thought was I shorted something while soldering, so I metered for shorts, and found a few. But I realized that it was actually pots set at the same extreme (0% or 100%) shorting to each other via the ground or +5v busses. If all the pots are set at roughly 50%, there are no shorts.
I just thought of adding resistors in series with each of the analog inputs, so that the resistance never goes to zero, but then I'd have to account for that by scaling the input somehow in the software... but I'm really only concerned about 0-255 resolution so that might not be such a bad thing... though it would require a LOT of re-soldering :(
Also, if anyone can point me to a good analog input smoothing function, I would be greatly appreciative.