[shakirfm] sent us this LED persistence of vision (POV) laser projector that can display dot matrix style text. The laser projector contains a rotating mirror assembly and 5 lasers. We’ve covered other POV projectors,but this one is a bit different. The mirror assembly rotates using two cooling fans. Controlling on/off times of the lasers along with the mirror speed, it is able to project 8×5 dot matrix ASCII text onto a surface.
The Atmel 89s52 contains a built in user interface which can control the horizontal character width, scroll speed and the number of characters displayed at a time. It can also store preset 10 character text messages internally, or accept text via the serial port from a PC. Eventually SMS messages from a GSM phone will be supported. [shakirfm] has more details and ideas for improvements here.