When [bornach] browsed through his office’s free-cycling box he found an old novelty toy that lets you play simple tunes on miniature steel drums. Such a thing is probably fun for about five minutes – if it’s working, which this one wasn’t. But instead of throwing it away, [bornach] spotted an opportunity in the capacitive touch pads on top of those little drums: they looked perfect to be modified into an unusual mouse cursor controller.
The operation started with [bornach] ripping out the original PCB and replacing it with an ESP32 D1 Mini. That board has a handy stack of touch-sensitive pins which could interface directly with the drums’ touch pads. He then programmed the ESP32 to interpret the signals as mouse movements and button presses, and send the results to a computer through a BlueTooth connection.
Operating the mouse drums is so straightforward that they almost appear made for this purpose: you slide your finger in circles along the touch pads to move the cursor in the X or Y direction, and touch the center pad to click. The left drum moves the cursor horizontally while the right one moves it vertically, but there’s also a mode to use the right drum as a scroll wheel.
The rotary X/Y controls are reminiscent of an Etch-a-Sketch; while probably too clumsy for everyday use, they might come in handy in some circumstances where you need to make single-pixel-accurate motions, if only to click those miniscule “close” buttons on some online ads.
Amazingly, this isn’t the first Etch-a-Sketch style mouse we’ve featured: this cute little wooden device works in a similar way.