How to pick the right Potentiometers

Hi I am making a bike handle with a Potentiometer attached to it so that the Potentiometer will rotate with the handle and the Potentiometer will be able to tell me what direction the handlebar is rotated.

The potentiometer will be powered by the USB of a computer or a battery (5 - 9 V, undecided yet)

I went to Digikey to buy them, but there are so many parameters to choose from, I have not idea what to look for.

Rotary - Linear | Digi-Key

Here are a couple parameters that I need help with: Resistance, Rotation, Number of Turns and Temperature Coefficient.

For example, in my application where my goal is to be able to read accurately the value of the pot so I know which direction and what angle the handlebar is, which resistance should I choose?

---------- Post added at 03:49 ---------- Previous post was at 03:45 ----------

my theory for resistance value is that the higher the resistance of the pot, the more variation I will get for my output voltage when I turn the pot, this will make my readings more accurate.

hi

i think you need to first finalize your application parameters, like how many rotations your bike handle is allowed to make. the temperature range in which circuit is to operate. as for the value i believe it will depend on the way you are measuring the resistance. 8)

Hi thanks for the reply.

the rotation will be limited to a max of 300 degrees, so I do think the single turn should be the best. My understanding is that if it's a 2turn pot, that means the resistance of the pot will vary from 0 to max when you turn it 2x encirclements.

As for temperature it will be in room temperature, so between 10 degrees to 30 degrees celcius. but what does it mean, or what is the application of ppm/C ?

lastly for the resistance value, we are measuring the output voltage. So we have a battery as the power source, we insert the pot and measure the output voltage

hi

i concur that 2 turn potentiometer will be best. potentiometer temperature characteristics won't bother you much in your current project.

use a ADC to measure the voltage at potentiometer wiper calibrate extreme left position, extreme right, and center position.