Project by Clewsy; VolCon

Clewsy just shared a new project: "VolCon"

This project began as an experiment when I inexplicably decided to learn how an optical rotary encoder worked (FYI, 2-bit gray code). It transformed into a learning experience around USB - specifically the HID protocol. Ultimately I ended up with a simple gadget that now sits on my desk and allows me to control the PC volume. A salvaged optical encoder was used to detect rotation along with a reclaimed head drum of a VCR which was repurposed as a control knob.

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Awesome project Clewsy! Love the wood/metal look that the body has. Does the encoder have a nice solid feel to it?

Hi Sam, thanks for the kind words.

The drum head I used for the spinner/knob is nice and heavy and its bearings are very smooth, so yes I’d describe the unit as solid. I also put some little rubber feet on the bottom - it doesn’t budge on my desk.

Nice Clewsy, gloriously named project “VolCon” and a great way to reclaim some retro bits-and-pieces for re-use!

Would be great to see a GIF or short video of it - mainly to get an idea of how it spins. There’s something about the “disproportional size verse purpose” factor of this gadget that makes it mildly awesome and definitely desk worthy!

Cheers Graham. During development I was calling it MedCon (media controller) but VolCon seemed a bit more accurate and a bit more interesting. :slight_smile:

I’m out of town for a few days but hopefully before next weekend I’ll have a *.gif put together and uploaded.


If you’re doing stuff with optical encoders then one improvement can be to use a JK flipflop to prevent the “going backwards” effect you get when you spin an encoder fast. The issue is that when you trigger a read on one input changing, by the time you read the second encoder input it has sometimes changed, giving the impression of turning in the other direction.
By using a JK flip-flop (which triggers on the falling edge of one encoder) you can easily latch the direction, and have two outputs, one that stays constant on direction and the other pulses at the speed of rotation.

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Awesome advice, love it!