Realizing that using a vanilla-ish arduino board will not yield good energy savings without heavy modding, we opted for a slightly more expensive, but function-packed option: Seeduino Stalker. The one we have is v3.0, arguably the windows 98 of the whole Stalker series according to some reviews. Thus far we encountered no problems migrating to the new, frugal platform. In fact, we were given a built-in RTC and power circuitry designed for a li-po battery from the get-go.

The best part about this migration is that, save for moving one pin to free the I2C interface, it is perfectly compatible with the sensor shield we used with Iteaduino. A pretty small price to pay for literally 100 times less idle current draw at 3V and a built-in RTC ready to send wakeup interrupts.

Coming up next: more detailed power consumption measurements, full-fledged sleep mode.