The new board is just 20mm x 20mm but is compatible with the much larger Arduino Uno.
If you're looking for a tiny board to build DIY hardware, they don't come much smaller than the Arduino-compatible Piksey Pico.
The board is the size of a bottle cap, just 20mm x 20mm, but supports the same selection of pins for hooking up homemade electronics as the much larger Arduino Uno and Nano, and should be able to replace these boards in many projects.
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"The Pico packs all the functionality of an Arduino Uno into a tiny form factor and can be powered through USB, as well as a range of batteries," says creator BitsNBlobs Electronics in a video.
Not only is it compatible with code written for these bigger boards, it also features a newer processor, the Atmel 328PB. Compared to the 328P chip found in Uno, this more recent processor offers two extra timers, twice as many communication interfaces, two additional I/O pins and 10 PWM channels instead of six.
BitsNBlobs Electronics have demoed the board in a range of homemade gadgets, including a battery-powered GPS tracker, a motion detector, and OLED room temperature display.
The Piksey Pico and its sister board the Piksey Nano, which uses the same Atmel 328PB chip but is a similar size to the Arduino Nano, are designed to help people learn about building electronics. Over the next few weeks BitsNBlobs Electronics will release tutorials on how to use common Arduino peripherals and modules with the boards.
The Pico is available for £11 (~$13.3) and the Nano for £12 (~$15.5). Both boards have been funded on Kickstarter and are expected to ship in December 2018 / January 2019.
For more information about the wider Arduino project and how it provides a simple way for people to get started creating their own homemade gadgets, check out TechRepublic's cheat sheet.