making an automated dispenser with a mega 2560
runs pumps for a few seconds in set patterns then waits for a period (somewhere in the region of 20 mins to 5h)
everything is working great but as its battery powered i need to reduce power consumption
im planning on putting it into sleep mode of some sort.
what options do i have to wake the arduino up after x time?
of those options what are the accuracy of them?
when people quote accuracy of 30mins +/- 1 mins. will it likely always be 31 or 29 for a given setup or will it vary each day?