As described in an earlier post, a potentiometer is essentially a variable resistor. It accepts voltage and varies the output of said voltage through another pin. This output can be interpreted as data by the microcontroller, and applied to anything that reads variable signal. Volume controls, LED intensity, clock speed, etc. In this case, the signal will be converted to MIDI data in software.
Here is an example of a simple LED dimmer circuit. In this example, no functions of the microcontroller are being used. It is only supplying voltage to the breadboard:
The potentiometer controls the amount of voltage flowing through the LED, thus affecting the LED’s intensity. Please note that the 330k ohm resistor in this circuit is crucial. If it is not included, the LED will burn out instantly from excess voltage.
The next post will detail a simple Arduino script to read analog data from the potentiometer and convert it to useful data.