My bedroom wall projector clock stopped working (not repairable), and I decided to try to build my own model, and this is the result. It consist of a very bright red LED seven segment display with a I2C backpack from adafruit, a DS3231 RTC from eBay, an Arduino Uno, a magnifying glass and a prototype case made of LEGO. Don't worry this is only a prototype I made to show the concept, we plan to build a more finished version with aluminium case later when we have better time :-)
In the meantime feel free to download my code and try to improve it!
Click on the picture to enlarge it and read our comments and advice
Check out this video of the LED watch filmed upside down and in a mirror.