This can be used to configure the ADC window interrupt on the SAMD21. It
uses OSCULP32K via GCLK6 to clock the ADC while in sleep mode (the same
as used for the EIC).
Note that attachAdcInterrupt()/detachAdcInterrupt() should be called
immediately before/after LowPower.sleep() otherwise analogRead() will
not work as expected.
There is also an example (AdcWakeup.ino) which is much like the
ExternalWakeup example but uses the ADC interrupt instead.
Waking from deepSleep() is comparable to an hard reset; the sketch won't restart from the sleep invocation but the wakeuup source can be retrieved with wakeupReason()
The includes and relevant (non wrapper) functions are borrowed from Zephyr 1.5.0
The implementation is still broken:
- an RTC driver is still missing, so no timed wakeup possible
- only the AON pins configured as LEVEL can wakeup the processor
on Arduino101, the only AON broken out is RESET button
Changing the main loop in CODK-A allows operating the button without triggering a reboot. However, the board doesn't wakeup from deep sleep (am I missing something maybe?)
