The default firmware for the module got an update. Now it works based on interrupts, so the cpu is in standby mode most of the time which has major power saving benefits. It wakes up once a second to do the readings and send them over serial, this works by using RTC overflow interrupt. Also it's waken up by pressing the buttons which starts a timer which tracks how long the buttons have been pressed to realize a smooth on/off operation.

Future firmware upgrades include a full separate i2c interface so Attiny can be accessed easily externally while also being a master for on-board devices.

Aside from firmware, EAGLE and KiCad footprints have been added.