I'm using led sticks (those plastic capsules with 5 piranha leds, including resistors, powered by 12V, using 50mA) to make a big clock. Since its a 6 digit, 7 segment display clock, this totals 42 led sticks.
First I was thinking of controlling them independently using 6 shift registers, but when I faced the amount of cables in front of me, I started to think about multiplexing. That would meake me save on cable, components and add not much complexity to the software. I've seen some posts talking about the trouble that is multiplexing big 7-segment displays, but no one about using these led sticks, nor what the problem was. Electronically I plan to use two shift registers (one for anodes, one for cathodes), one ULN2003 for sinking current and six BC327 transistors (one for each digit). Does anyone have experience with them? Hope I can build something to test it during the weekend. Worst case scenario is that it flickers or light is to dim, right?