Electronics enthusiasts continue to impress with their creativity by designing unique homemade gadgets using Raspberry Pi microcomputers. The latest innovation comes from developer Kim Paulsson who showcased a wristwatch dial based on the RP2040 microcontroller found in the Raspberry Pi Pico.
Instead of traditional watch hands, this wristwatch displays the time using a ring of bright RGB LEDs. Paulsson created this project as part of a learning exercise, designing a circular printed circuit board with a 28.5mm diameter to serve as the watch face. The device runs on battery power for autonomy and includes an LED strip along the perimeter of the board.
The LEDs on the board illuminate in different colors to indicate the hours, minutes, and seconds. However, since this is a PCB prototype and not a finished product, the LEDs may appear too bright. Paulsson suggests solving this issue by adding a diffusion layer, possibly created using a 3D printer.
The circuit board was designed using the KiCad automated design system specifically for this project. The device sports a matte-black finish and utilizes surface-mount components, including the RP2040 chip as the main processor. To store programs, a Winbond 25Q1281VSQ 8Mb flash memory chip is included since the RP2040 lacks built-in memory. Additionally, there are 60 LEDs surrounding the board – one for each second as well as for indicating hours and minutes. While the specific LED type used is unspecified, they likely are WS2812 or APA102 LEDs that require power, ground, and data connections.
A video posted on YouTube by Paulsson demonstrates the working wristwatch dial with the RP2040 microcontroller, proving its functionality. Next on the developer’s agenda is optimizing power consumption and designing a case to house the electronics. In the meantime, enthusiasts can enjoy the mesmerizing glow of this homemade gadget.