At Ohmify we are definitely into Arduino and motors. In fact, we just recently released an entire course on learning how to control different types of motors using the Arduino.

Some of the most common motors you’d use with an Arduino are DC motors, servo motors, and stepper motors.

This week’s entry takes a look into stepper motors and how Jonathan Kayne used stepper motors to make music. Before you ask: it is not the stepper motors controlling an instrument. The stepper motors are the instrument!

First, what is a stepper motor? Briefly: a stepper motor is a motor that you can move in steps and are often used in machines. For example: 200 steps per rotation. So if you tell your motor to go 100 steps in one direction, it will turn exactly 180 degrees.

While they turn, stepper motors often create a hum that is dependent on the speed that the motor is spinning at. In this project, MIDI data is used to “play” the stepper motors. In short: MIDI (Music Instrument Digital Interface) is a communication protocol that sends messages to a wide variety of electronic instruments and devices.

MIDI doesn’t make the music itself: rather, it is an interface that communicates to the device various instructions. For example: whether a note should be played or not played.

By writing and sending music using MIDI to the stepper motor, you get a song. The initial version of this project used only an Arduino UNO but as the design became more complex a FPGA (Field Programmable Array) was used. FPGA allow for more customization and processing power.

Ready to take a listen?

If you’d like to learn more about Jonathan Kayne’s stepper synth , stop by the project page here:
https://sites.google.com/a/vt.edu/amp_lab/projects/stepper-synth-v2#h.p_soQXCzLxfbHY

And if you would like to listen to more stepper music made by the stepper synth, Jonathan has many more examples on their YouTube page:

What do you think about making music with a stepper motor? We’d love to hear your thoughts in the comments below.

Have fun everyone!