Setting Thresholds in Hardware
The sketch above set a threshold – a value that defines how much change is expected before something happens – in the program code. Depending on your environment and application, it may be necessary to adjust that threshold. To avoid having to connect the Arduino back to the computer and reprogram it, you can use a potentiometer (“pot”) to adjust the amount of resistance in the circuit.
You can connect a pot in many ways, an example of which is shown below: