Water Sensor

The water sensor project was completed in January 2018.  It is an attiny 85 microcontroller running on a 9V batter.  The voltage regulator is an ultra low quiescent current 3.3 V supply.  It checks for water every 10 minutes and otherwise sleeps at 8 second intervals only waking up to go back to sleep.  Should the battery voltage drop to approximately 6V or water be sensed, then the buzzer goes off to alert the user.  It is intended that the battery will last for years.

Completed board

PDF of the schematic

Microcontroller Code