needed a 16 bit fine control in an experiment and I realized it with two potmeters, one for coarse and one for fine control
After some tweaking I got this more generic function
uint16_t analogR(uint8_t coarsePin, uint8_t finePin, uint8_t bits) // bits = bits per potmeter 1..8, so the result will be twice that nr of bits.
if (bits > 8) return 0;
uint8_t shift = 10-bits;
// analogRead(coarsePin); // opt. to remove noise by double read
uint16_t value = (analogRead(coarsePin) >> shift) << bits;
return value & (analogRead(finePin) >> shift);
I restricted the number of bits per pot to 8 to minimize noise fluctuations.
thoughts for improvement:
* three pots? four?
* why restrict both pots to same # bits?
* how to do odd # bits? e.g. 15 bits so I could use the sign bit for errors.
just to share