askoog89 saw a major flaw with many LED watches – you have to press a button to see the time:
A Watch
I tried fix that problem by using a tilt switch to active the LED showing the time when tilt your arm to look at the watch
The watch uses the low power MSP430G2211 MCU from Texas instruments to control the LED and mesure the time with the help of a 32kHz watch cristal. The MCU sleeps most of the time only waking up ones a second to count up the time and check if the tilt switch is active. To show the time the watch uses 12 charlieplexed orange LEDs.
OSH Park 