This is an old revision of the document!
The LED clock is an add-on for round wall clocks. The purpose is to have LEDs on the circumference of the clock to show the progress of the time using coloured light.
For that you will need:
WS2812b RGB LEDs strip (long enough to go around the clock)
development board with a STM32F103 micro-controller and 32.768 kHz oscillator for the Real Time Clock (such as the blue pill)
coin cell battery to keep the RTC running (optional)
GL5528 photo-resistor to adjust the LED brightness (optional)
More details about the project can be found in the README.
The code for the micro-controller is available on git.
It includes the script to compile the code, flash the firmware, and generate the source documentation is included.
A release with sources, compiled firmware, and documentation is available here.
Here I will only put picture to show how it looks like.
Here is the LED clock add-on:
WS2812b LED strip
blue pill development board with STM32F103 micro-controller
USB for power, SWD adapter to flash, USB to UART converter to debug
tiny RTC i2C module with Maxim DS1307 RTC IC
CR2032 coin cell battery