I have a 1 turn 10k Ohm Potentiometer attached to the analog input of an Arduino. Now, the full range of the pot gives me values from 0 – 1023, nothing new.
The problem: I only want to measure change within a small rotation range of the pot. So the start position is at 30° rotation and the end position is at 40° rotation. I want to achieve a maximal numerical range within those 10°.
Are there any potentiometers that don't turn about 270°? Or can I maybe achieve it by putting more resistance in line?
Appreciate the help!
Thank you,
Marcel
Best Answer
Try this circuit, using 2 pots; its standard method to set coarse, and then fine voltage into ADCs, to examine how the output code bits vary to ensure there are no missing codes
simulate this circuit – Schematic created using CircuitLab
you may need to insert R8, and use the top node of R8 as your output RTN node, thus allowing testing somewhat below 0volts Vout.
Make the capacitor as large as possible, electrolytic if you wish. Watch out for microphonics (vibration sensitivity) of ceramic caps.