Any interest in connecting the OUT/SQW pin on the RTC to the power button pin on the BBB? It looks to not be connected to anything on the schematic. I think the BBB itself has both an RTC and watchdog, but using either means keeping several of Opensprinkler and BBB power supplies running all the time…
Might be interesting to have the BBB power off at night in an off-grid scenario.
BBB does have RTC, but it doesn’t have a built-in battery. So when designing OSBo, I included a DS1307 RTC with CR1220 battery. I am not familiar with the way you described: connecting the OUT/SQW pin on the RTC to the power button pin on the BBB. Would this trigger a periodic reset or something?
Basically you can tie it into the BBB’s soft power button (it’s on the BBB header) so the RTC powers the bone on whenever the alarm is programmed to fire (alarm times are programmable via I2C). This could be useful if you want to run the controller with battery/solar power, and wake the bone before the next scheduled event. For instance you could have the BBB power off overnight (or when solar input voltage drops below a threshold), between scheduled events, etc.