A talented Maker by the name of Zak Kemble has designed a rather impressive DIY wristwatch powered by Atmel’s ATmega328P microcontroller (MCU).
“The main incentive behind this project was to see how much I could cram, in terms of both hardware and software, into a wristwatch-like device that is no larger than the display itself,” Kemble wrote in a recent blog post.
“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″ display, but this proved too difficult to get all the things I wanted underneath it. Going up a size to 1.3″ was perfect.”
Aside from Atmel’s ATmega328P, key project specs include a 2.5V regulator, Maxim DS3231M RTC, 1.3″ 128×64 monochrome OLED, 2 LEDs (red and green), two PCBs, a buzzer sounder, three-way switch for navigation and a 150mAh LiPo battery which can be charged via USB.
On the software side, Zak notes that he spent “a lot of time” optimizing the rendering code which involved copying bitmap images from flash to the frame buffer in RAM and sending the frame buffer over SPI to the OLED.
“The end result was being able to maintain 100+ FPS in almost all areas of the watch with an 8MHz AVR,” he explained. “However, since the animations are frame based instead of time based and to save power, the frame rate is limited to 60FPS.”
Interested in learning more about Zak Kemble’s DIY digital wristwatch? You can check out his official project page for additional details and schematics.
Atmel | Bits & Pieces 