Volume Control Knob and Start/Stop Button Accessory

After signing up for Spotify Premium, I found that I often needed to stop and start songs to concentrate on various tasks, as well as adjust the volume. My keyboard had shortcuts built in, but as seen here the ergonomics weren’t exactly to my liking.

What I needed was something that had start and stop buttons, and a knob to control the volume. That way I could do these tasks without moving my mouse or trying to stretch my fingers to hit the function key and whatever else was required. What I came up with can be seen in the video below, using an encoder to indicate which way is turned by the knob to the computer. Along with a button, this should give me all the control I need:

To interface with the PC, I chose a Trinket board from Adafruit (also available here on Amazon). After a very brief amount of searching, I found that someone else had already thought of this, providing code and schematics. Originally, I thought I’d use a series of resistors in order for me to use multiple buttons, but this was easier said than done due to the way the board is made. I instead settled for pretty much their exact setup. Here is my very lightly modified code.

Given this, I could have done away with the yellow button, and just used the one built into the encoder. For whatever reason I kept it, and it did make for a nice display in the end. In order to get the button to stick out just a little bit, I put a piece of scrap MDF under it before soldering everything, making the world’s worst soldered breadboard.

Finally, it was time to make the body of this device. I drew it up on CAD, then cut it out of MDF and white acrylic on my CNC router. I didn’t leave quite enough clearance in my design, so I took more material out of the MDF base using my manual mill.

I then cut the top out of white acrylic, and it was time to see if everything fit together. With everything in place, it was time to paint it black with spray paint, including a control knob I also cut out of MDF. And Viola, it now fits together and even looks pretty good!

I applied wood glue to stick the two halves of the housing together. Once attached, this clamps the circuit board into a thin recession between the two sections I removed the excess glue with a scrap piece of MDF, then checked to make sure that everything fit together correctly. Clamps were then applied, and I let it dry overnight.

Now my problem is solved. Rather than fumbling around on my keyboard, I can simply reach over and adjust the volume with my new knob. If I want the music to stop, there’s just one button to hit for that!

Additional Thoughts

Admittedly, this device takes a while to register button presses and knob input, which I haven’t quite figured out yet. Also, after disassembled to take a picture of the internals yesterday, it seems even more inconsistent! I’m really missing it’s ease-of-use today, so I guess it was a good project. Also, it was great to learn about encoders through it.

Finally, for the control box that partially inspired this build, check out this video. No encoder, but it does have four buttonsĀ  and additional interface settings:

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