We’ve covered many boards that claim to be the world’s smallest development board, and Tomu board does not claim anything like that, but it’s pretty small, as it’s made to fit into your computer’s USB board. It may be cool, but it could also potentially be useful, as the board exposes two (capacitive touch?) buttons, and two LEDs so you can use it as a computer accessory for example to add volume buttons, or as a Universal 2nd Factor (U2F) token supporting two-factor authentication (2FA) to login to compatible online services.
- MCU – Silicon Labs Happy Gecko EFM32HG309 ARM Cortex-M0+ up to 25 MHz with 64KB flash, 8KB RAM
- USB – 1x USB 2.0 FS port
- Misc – 2x buttons, 2x LEDs: 2 (red + green)
- Dimensions – 1.4mm thick (0.6mm thick PCB)
Singapore based Sutajio Ko-usagi – the company behind the project – provides the hardware designs files (KiCAD + gerber), and source code for the board on Github, so you can modify the hardware and/or software to meet your requirements. A mailing list and #tomu freenode IRC channel have been setup for support.
Since the project, now launched on Crowdsupply, have now raised way more than the $2,000 stretch goal, a plastic case will also be offered with the board. Pledges start at $30 for a single Tomu board, which is quite pricey for a single board, but other rewards bring the unit price down, as you can get two for $35 ($17.5 per board), and up to 1,000 boards for $8 per board. Shipping is free to the US, $5 to $50 the rest of the world depending on the rewards, and delivery is scheduled for August 2018. Tomu.im website provides a getting started guide, and also explains how to use Chopstx with U2F support on the board if you are interested in two-factor authentication.