We have to admit that the DIY space sometimes seeks to answer strange questions no one has asked. For example, how crazy would it be to build the world's smallest keyboard, add RGB lighting, and try to play Helldivers II? Juskim on YouTube is known for his experiments with keyboards and mice. A couple of months ago he tried to resolve that doubt, and the process turned out to be much more complex than we imagined…
The smallest keyboard I've had on my desk was a BTC-5100C. 30 x 15 centimeters, 81 keys, silent. It's not a terrible experience, but its format is uncomfortable for most users, and the PS/2 connector doesn't help on modern equipment.
Of course, there will always be a time and place for compact keyboards: Smart TV remotes come to mind immediately, as does server access, and there are always those who connect physical keyboards to their tablets to enter text and commands faster. In fact, we've used tiny keyboards for years (e.g., BlackBerry), until touchscreens conquered the world. But what's the most absurd extreme? How small can a functional keyboard be?? Juskim on YouTube decided to find out…
The World's Smallest Keyboard Has RGB, and It Works
From a general point of view, this keyboard represents version 2.0 of the mini keyboard Juskim built in February 2023, but he took the opportunity to make some optimizations. The original keyboard doesn't have number keys, so the new design brings them back, along with square bracket keys ([], + and -). The space bar also caused problems in the initial model, and he solved them using additional switches.
Now, none of this would be possible without the adoption of ultra-compact switches, combined with BAW56S modules, which contain four diodes per chip. The PCB needed four layers (PCBWay came to the rescue here), and a hotplate simplified soldering the switches. The keyboard's "brain" is a classic ATmega32U4 with USB support, essential for running a "60% keyboard" firmware.
The final dimensions of the keyboard with its bare PCB and exposed switches are 66 x 21 x 5 millimeters. That makes it smaller than a BlackBerry keyboard, and includes more keys. Logically, pressing them is a nightmare. Even with printed keycaps (which have to be glued onto the switches), even the simplest tasks are like swimming in jelly... but at least it has RGB. (!)
