Like most people, you probably use a keyboard and mouse (or touchpad) to interact with your computer. Those are, of course, very versatile input devices that can handle just about any task. But sometimes you want the convenience of physical hardware controls for repetitive tasks. An external button or dial can add a great, tangible way to control common functions. If that’s something that appeals to you, Prusa Printers has a YouTube video guide explaining how to 3D print a customizable medial control knob.
This media control knob is very simple, and has default functions for turning your volume up or down, playing and pausing music, and skipping to the next track. To build it yourself, all you need is an Arduino Pro Micro, a rotary encoder, and access to a 3D printer. The rotary encoder is a simple component that can spin infinitely in either direction — like many volume knobs on audio equipment — and can also perform as a momentary button. The Arduino will act as an intermediary between the rotary encoder and your computer in order to send the proper control commands over USB.
The first step is to use a 3D printer to print the physical parts of the control knob. There are a few different style options to choose from, or you can model your own in CAD. Then follow the instructions to connect the rotary encoder to the correct pins on the Arduino Pro Micro. Next, you can upload the provided code to the Arduino. That’s when you can modify what commands the knob sends to your computer, or you can stick with the defaults. Test the knob to make sure it’s functioning correctly, and then assemble the 3D-printed parts. Now you’ve got a simple and affordable external hardware control knob!