Tutorial 4: Interrupts
Hardware interrupts are an incredibly useful feature of the Arduino. Interrupts make it such that you don't miss an input event like the push of a button or a pulse from another device. Instead of actively polling a pin for input you can let your program do other things until the interrupt is triggered. Once interrupted, the Arduino will call a specific subroutine. Interrupts are important for time sensitive tasks such as button presses or timing signals.