Potentiometer
A potentiometer is a three-terminal variable resistor. Turning the knob changes the voltage seen at the middle terminal when it is wired as a divider.
Part images
What it is
A potentiometer is a three-terminal variable resistor. Turning the knob changes the voltage seen at the middle terminal when it is wired as a divider.
How students use it
Students use it as a knob for brightness, speed, volume-style controls, thresholds, servo angle, and analog-input practice.
Pins and power
Three terminals: two outer ends of the resistive track and a middle wiper that moves as the knob turns.
Passive part. For Pico lessons, connect the outer terminals to 3.3V and GND so the wiper stays inside the ADC range.
As a voltage divider, the middle pin is the ADC signal. Swapping the outer pins reverses which direction makes the reading increase.
Voltage and safety
Never feed an ADC pin above 3.3V. Use 3.3V as the high side of the divider, not 5V.
Power off while wiring the outer rails. If the knob behaves backward, swap the two outside pins instead of changing code first.
Module internals
Resistive track, rotating wiper, three terminals, knob/shaft, and housing.
Datasheet notes
SunFounder explains potentiometer behavior but does not list the kit part resistance or manufacturer. Read the printed value on the part before matching a datasheet.
Common libraries
Use machine.ADC to read the wiper voltage. Use filtering or averaging when a project needs smoother values.
Common mistakes
Connecting the wiper to 5V, using the wrong ADC-capable Pico pin, leaving one outer pin disconnected, and expecting perfectly stable readings without smoothing.