Music volume is a personal thing, and often needs to be adjusted—or even turned off—at a moment’s notice. Sure, you could mouse over to Spotify or whatever you’re playing and adjust things via mouse input, or even use a keyboard shortcut, but you may prefer a dedicated rotary input for this task. While some keyboards do have this functionality, Glen Akins decided to make something much more awesome, a PIC-based volume/mute knob in a custom 3D-printed enclosure.
The device runs on a PIC16F1459 microcontroller, driven by a fairly high-end Grayhill 62S11-M40-020C rotary encoder. The housing was designed in Fusion360 using a parametric modelling process, meaning that everything can be modified as needed to create an enclosure just the right size. In fact, Akins made the general enclosure package a few months ago, and the volume knob build just happened to be the first project that came up. He created an empty PCB board outline in Fusion to hold the electronics, then exported as a DXF into Eagle PCB to form the base of the electrical design.
The housing was printed using a 3D print service, producing a really beautiful finished product. From there is was “just” a matter of programming the PIC, adding knob to the top, and screwing it together with a few bolts. A Micro USB-B cable is then attached to the back for proper rotary volume control!