I just got done wasting 10 very frustrating hours on a Interrupt Service Routine problem.  In this case it was a pin change interrupt that causes the chip/board to reset.  It turned out to be a simple capitalization error but luckily I also discovered some info about the AVR default ISR.  I wanted to post it here in case somebody accidentally found it useful.   Continue reading “AVR (& Arduino) Default ISR – Resetting Pin Change Interrupt Problem” →