"The pin "AD0" selects between I2C address 0x68 and 0x69." -> 3.3V
Third base sensor:
Sum up and devide.
Calibration -> needs on/of switch, begin vibrates, end vibrates
Tolerance needs to be settable -> poti...
Maybe Cases to log the events. (Grades/Magnitude of variance)
Store data on EEPROM, with time...
Maybe RTC modules? Not for MK2