Most persistence of vision (POV) projects are very hard to time – questions arise one when to start the sequence of On’s and Off’s to make the pattern of lights. It’s not really that difficult to do the timing but it requires a certain skill and an awful amount of patience. Most of the existing POV units has a synchronizing signal – this may be a opto interrupter, a line sensor or even trip switches switch made out of dangling wires!
To make it more sophisticated Rucalgary built a tiny POV with just seven LEDs an ATMEGA48A and a MMA7660 accelerometer from freescale – no he is not advertising its just way too cheap. The accelerometer is used to determine when to start displaying the messages – one more thing that separates this from most POVs is that it has multiple messages stored in an EEPROM – which the microcontroller fetches to display while spinning.
He is selling these for to help his college so if anyone wanna help out grab one!