Step 12: Testing and Troubleshooting

Now let’s make sure our system works as expected before moving on to mounting the control unit near the washbasin.

1) Disconnect the Arduino from your computer.

2) Use your external power supply to power up the entire system.

3) Press down on the pushbutton and release it to check if the status indicator LED lights up and the solenoid valve opens and both remain active for 2 seconds.


1) Status indicator LED doesn’t function:

> Check if the connections are right.

> Check if the LED is healthy.

2) Solenoid valve doesn’t function:

> Check if the connections between the motor driver IC and the Arduino and the solenoid are right.

> Check if the solenoid valve is healthy by externally exciting it.

> Check if the IC is healthy.

> Ensure the external power supply is adequate.

3) Both the LED and solenoid don’t work:

> Check if the pushbutton functions properly.