Project number : 25 (Basic water level indicator).
The project works as follows :
When the water in the tank is less than 25%, a buzzer works with a loud sound and the colored LED lights up. When the water in the tank reaches 25%, the red LED lights up, at 50%, the yellow LED lights up, at 75%, the blue LED lights up, and at 90%, the green LED lights up. When the water reaches the highest level in the tank, the buzzer works but with a low sound. It can also be turned off using the switch.