This DIY “Mouse Ring” Is a Compact Wonder
Juskim made another tiny mouse, this one worn on the middle finger like a kind of electronic thimble.
For all of the last third of the last century, the tech industry was intent on miniaturization. That’s how we went from mainframes the size of school buses to powerful computers that fit in our pockets. But sometime around the turn of the century, we started to realize that most things were small enough. However, makers now have access to components and fabrication processes that used to only be accessible by industrial giants and many of us want to try our hand at tinifying things, too. Juskim has completed several such projects and his newest is this DIY “Mouse Ring.”
Juskim has a bit of an obsession with small things, including tiny keyboards, tiny PCs, and tiny RC cars. But he seems to have a particular fascination with mice and has made several of the “world’s smallest” mice. This latest project is a combination of those and his “world’s lightest” mouse. The term “ring” is a bit of a misnomer and “thimble” would probably be more appropriate, as it slips over the last digit of the middle finger. An optical sensor detects movement to move the cursor, just like on any other modern mouse. But instead of conventional buttons, it has proximity sensors — the user only needs to tap their index and ring fingers for left and right clicks.
Oh, and it is wireless, since a USB cable would diminish the mini effect and add drag during gaming sessions.
The project started with simple prototypes built using circuitry and components from the previous World’s Lightest Mouse project, along with several 3D-printed iterations of the enclosure to nail the form factor and comfort.
With the basic concept figured out, Juskim moved onto the miniaturization. The optical sensor was already quite small, but everything else was pretty big—especially the Arduino Pro Micro development board and proximity sensors. He replaced the former with an ATTO, which was advertised as the world’s smallest Arduino-compatible development board. It doesn’t seem to be available anywhere anymore, but it is very, very small. Juskim then replaced the latter with tiny proximity sensors from STM. A wireless transceiver (actually integrated with a microcontroller of its own) and an itty-bitty lithium battery paired with an even ittier-bittier charger rounded out the BoM.
It took some fiddling with the code to get usable performance, as there was noticeable lag caused by the proximity sensors. Juskim also reports that the mouse was uncomfortable to use for an extended period of time. He has ideas for improvement, but either way the Mouse Ring is an interesting lesson in miniaturization for makers.