In this video, Steve builds a 6 digit LED clock from some Kingbright SA23-12SRWA 7 segment displays and a Microchip PIC18F26K20 microcontroller. You can build one for yourself with the schematics posted under my LED clock page http://www.youtube.com/watch?v=Ov27rac0tP0
In this video Steve interfaces the DC-DC converter circuit with a Microchip dsPIC33FJ16GS502 microcontroller to create a microcontroller-based constant current LED driver. The dsPIC33FJ16GS502 microcontroller has four analogue comparators which allow expandability to 4 independent constant current channels. http://www.youtube.com/watch?v=Jcble4aiNlw