Hi, I'm in the process of using 3 or 4 74hc595 shift registers to control a pov display I'm trying to make. I use a hall effect sensor (finally working!) to keep track of rotations.
I haven't hooked both systems up together yet (leds AND hall effect), so I'm not sure how this is going to work. if I use attachInterrupt on the hall effect sensor to call a function that adjusts for any small change in motor speed (it seems to vary between 900-1000rpm), will that completely destroy the data going out to the shift registers at that point? because, well, its interrupted... :)
also, I have 27 leds. If I use 3 shift registers for the first 24, will hooking the last 3 directly up to the arduino alter their timing any? I don't know if there's a noticeable delay between turning on an arduino pin, or sending data out through 3 daisy-chained shift registers