- Published in issue 9/2018 on page 90
Nostalgic LED Clock
74xx around the clock
In this project, an analogue wall clock (train station clock) is fitted with 60 LEDs that light up to simulate the movement of a seconds hand around the clock face. To keep to the spirit of this project you should try hard and resist the temptation to use a microcontroller; just rely on good-ol’ 74xx TTL logic to build a stand-alone clock. For those with less willpower the circle of LEDs can be microcontroller or PC controlled, this allows you to be a bit more creative with lighting sequences and special effects.