In the water level sensor schematic, the common probes connecting the underground tank and the overhead tank to +9V supply are marked ‘C’. The other probe in underground tank, which is slightly above ...

The hardware is consists of an Arduino microcontroller (here an Arduino Uno R3) and a pre-wired soil moisture sensor module. The soil moisture sensor module , built around the LM393 comparator, gives ...

As the water rises it completes the circuit, illuminating the LED. [Raikut] is conservation minded and built a buzzer circuit which is activated by the LED indicating the highest water level.