slot sensor

Novice, trying to setup an Arduino Nano with a slotted optical switch so that it tells me when a blade (in a disk) has passed through. slot onlie The disk will be spinning at varying speeds. slot berlisensi The switch has an analogue and digital output I am using the digital output (connected to pin D2), I think it uses a Schmitt trigger to give 0=open, 1=blocked I have used interrupts with a Falling edge and as you