The main incentive behind this project was for the maker to see how much he could cram, in terms of both hardware and software, into a wristwatch-like device that is no larger than the display itself. An OLED display was chosen for being only 1.5mm thick and not requiring a backlight (each pixel produces its own light), but mostly because they look cool. The watch was originally going to have a 0.96 33 display, but this proved too difficult to get all the things wanted underneath it. Going up a size to 1.3 33 was perfect.
On the hardware side the watch contains an Atmel ATmega328P microcontroller, 2.5V regulator, Maxim DS3231M RTC, 1.3 33 128×64 monochrome OLED, 2 LEDs (red and green), a buzzer sounder, 3 way switch for navigation, powered by a 150mAh LiPo battery which can be charged via USB and 2 PCBs (though one PCB is just used as a raiser for the OLED).