This code tracks PIR events using an SD shield with Real time clock.
First time usage of the SD card shield requires setting the RTC. Uncomment set_rtc_time_from_compile()
in the sketch, and upload. It will blink quickly until power is removed.
Now comment out the set_rtc_time_from_compile()
method and upload again. It will blink 10 times very fast to indicate its succesfully initialized and ready to log data.