Today's goal is to measure the time between external interrupts.

External INT on a PIC16LF1708 is on RA2. Use the internal weak pull-up.

It's not that easy to find where to set, so I'll put it here. Use MCC's Pin Module to enable the register. In order to set individual pull-ups (rather than a whole port at once), the WPUEN bit must be enabled.

Then:

• Go to ISR
• Set Timer0 to 0
• Count until next EXT interrupt // here I am using a wire on A2
• Timer0 = elapsedTime
• elapsedTime - 0 = time
• Timer0 = 0