See http://www.piclist.org/techref/microchip/qenc.htm . The use of the state machine in that code deals with contact bounce (which is a pain!). I agree that you should not do interrupts on the encoder itself. You'll get an interrupt on every bounce. A timer interrupt and then check the inputs should be fine. Then run the state machine. Good luck! Harold --=20 FCC Rules Updated Daily at http://www.hallikainen.com - Advertising opportunities available! --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .