USB Volume Knob Device

thingiverse

If you're tired of fussing with your keyboard to adjust the volume on your computer while lounging back and watching movies, and if your speakers and the volume knob are positioned out of reach, try this dedicated USB volume knob. This is a USB volume knob device designed to house a rotary encoder and an Arduino-compatible Adafruit Trinket. The setup is detailed on Adafruit's excellent website: https://learn.adafruit.com/trinket-usb-volume-knob/overview Common Issues With Trinket If you've never worked with Adafruit's Trinket board, carefully read the setup instructions: https://learn.adafruit.com/introducing-trinket/setting-up-with-arduino-ide You'll need to install this driver first: https://learn.adafruit.com/introducing-trinket/windows-setup Hit the reset button on the Trinket before hitting the upload button on the Arduino IDE to upload the sketch. Experiment with the timing – for ours, we had to hit reset and immediately hit upload after hearing the USB disconnect chime on our desktop. We permanently soldered the wires from the encoder to the Trinket, so be extremely cautious when wiring your project. Switched wires can burn out your Trinket! Concrete Infill You can make this as is, or you can mix 3 parts sand and 1 part cement and add a concrete infill as pictured to give it a nice weighted feel. The knob comes with a cover, so you can add concrete inside the knob and then friction weld or glue the cover in place. Leave the concrete to dry overnight. Test fit the knob cover to ensure you didn't add too much concrete. If there's excess concrete, the next day you can still scrape out the excess material and fit the cover. Other popular infill methods include hot wax and metal pellets – we didn't try these because 3D printing uses thermoplastic and heat could warp the parts. Securing the Knob To secure the knob onto the rotary encoder, use some hot glue. We used an earlier knob version with a semi-circle interface that didn't fit our encoder, so we drilled it out – but now the knob is slightly lopsided. The knob included in the STL files is a full circle, so you'll need to glue it in place to secure it to the rotary encoder. Double-check alignment to avoid leaving it lopsided. Securing the Rotary Encoder Since we don't know what type of encoder you have, we made the encoder bracket a separate part that can be redesigned in SketchUp to fit whatever one you have on hand. It's essential that the encoder sits in the channel centered. We friction welded the bracket in place and used a dab of hot glue to secure it after prototyping was done.