Raspberry Pi Pico

A potentiometer is a variable resistor. As a minimum, you are talking about three pins. One pin connects to GND, one to power and the other one (the 'wiper') is the one you take analogue readings from.

There are 3 usable ADC channels on the Pico are connected to GP26, GP27 and GP28. You can get a 12 bit reading from the ADC but this will be returned to you mapped onto a 16 bit range.

You can see a 10K potentiometer connected to GP27 in the following photograph. Next to the board I have placed two other potentiometers. The little blue ones are the cheapest but, if this is what you have in your kit, be careful with the pins when placing in a breadboard and when using. The pins are really thin and easy to break.

Pico Circuit

Here is a Fritzing diagram for the same circuit,

Pico Circuit

Here is a basic program to read the potentiometer and output the reading to the shell. I get readings from 256 to 65535. You may find that you get slightly different numbers at the extreme ends. This depends on your potentiometer.

from machine import ADC
from time import sleep

pot = ADC(27)

while True:
    reading = pot.read_u16()