Display multiplexing -- at 32.768Mhz, there is bad flicker. At 131.072kHz there is noticeable flicker, but not too bad -- sort of like a fluorescent bulb, where occasionally you can see the flicker. 1Mhz would cure that for sure. Yes, I've tweaked and tweaked and tweaked to try and reduce the loop time and the display transition time. I'm thinking even 200khz might do the trick though. Cheers, -Neil. -----Original Message----- I like to use 32.785 Khz watch crystals for timing things. The added benefit is low power, because of less transistions of the PIC oscillator and associated stuff. The crystals are quite accurate, and the PIC doesn't care how slow it goes. I can't imagine anything that has to happen at >1MHz in a dog feeder. --Lawrence -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.