How would I use a RTC (such as the DS1307) to trigger an interrupt? The overall goal is to put the processor to sleep and then wake it after an hour or so. I looked at using a watchdog timer, but it only goes up to 8 seconds and is reportedly unreliable.
Other info: Data logging kit w/ RTC - http://www.adafruit.com/products/243 Fourm post that alludes to using an RTC as an interrupt - http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1291420085 Watchdog tutorial - http://interface.khm.de/index.php/lab/experiments/sleep_watchdog_battery/ RTClib - https://github.com/adafruit/RTClib
To clarify, I understand how interrupts work; I just don't know how to implement one using the RTC. I don't get how the interrupt is supposed to trigger if the RTC has to be called to get the time (The code uses
DateTime now = RTC.now(); to get a snapshot of the current time).
tl;dr How do you trigger an interrupt using an RTC such as the DS1307?