Testing a potentiometer for noise using a scope

I can't believe I never thought of this before. I guess this is the price to pay for having learned electronics on the web.

Connect 5V to one of the pins, connect the oscilloscope probe on the wiper, turn the knob. If your pot is clean, the trace will move from 0V to 5V without noise.

https://youtu.be/yx5JyniOrp4?feature=shared

But since the wiper will sooner or later get dirty, a cap on the wiper to ground will control this.

Ioannis

Yup.

I'm putting all my components on a separate board with I/O expander, nothing on the individual switch boards.

It'll help keep costs down. Empty circuit boards are relatively cheap.