Automatic Water Tank Pump Switch Hardware • Microcontroller Unit: The designed circuit shown here includes an Atmega328P-PU as the kernel, a number of LEDs to display the system status, a push button ...

Since he had the ability to toggle the pump on and off with a relay attached to the Arduino, [Luc] decided to add in a few other features.

The Arduino manages everything else on the system as well including all of the temperature sensors and fan motor control.