Inside is Arduino Pro Micro and a PMW 3389 optical sensor on a breakout board. [Ben] was going to use flexible 3D printed panels as mouse buttons, but then had an epiphany — why not use keyboard ...

Posted in Wireless Hacks Tagged arduino pro micro, energy meter, kill a watt, nRF24L01+, power meter, spi, wireless. ... There is even a dial that can turn up and down the brightness.