Here is another interesting DIY project using LED’s to create a digital clock, this Persistence of Vision (POV) LED Clock looks fantastic!
This POV LED clock works by having the LED‘s flash at certain moments as it spins around which creates the image of the clock. The clock achieves this by using PCB blades which are then spun around using a PC cooling fan spinning the blades around creating the image of the clock. The image is created by the LED’s illuminating which have been synchronised with a Hall Effect sensor, this creates a persistent image to the human eye even though this is not actually the case. To actually power the clock it is powered wirelessly from a base transformer which transmits to a coil on the board.
The clock is always changing as it is receiving a lot of information from the custom firmware it is using, this custom firmware has 3000 lines of code (yeah there’s a lot going on in this clock), but what this means is unlike other clocks you can actually do a lot of tweaking with it. The clock uses a fair few parts including: an ATmega324P @ 20MHz, a 64kb Ramtron FRAM, FM1608, 5 x TLC5916 constant current LED drivers, 40 x Cyan PLCC-4 LEDs, A1101 Hall IC, TSOP6238 IR receiver and MIC5209-5.0 LDO V-reg.
This video here shows the first version of the clock version 1.0 and all of the parts in which it is made up from.