The coronavirus is now affecting everyone's life, and washing our hands became very important tasks in our daily life. It is a very easy thing. It is about timing the handwashing time, so it can help you when you are washing your hands.

Thanks for the credit by https://www.instructables.com/id/Simple-Handwash-T...

I change the handwash timer by adding a speaker in it, it can help the user listen the sound of it.

Step 1: Step 1 : Get All You Need

There are only several things that you need to prepare for doing this project

Arduino Leonardo

HC-SR04 Ultrasonic Distance Sensor

1 Red LED

1 Green LED

4 Blue LED

Enclosure

Breadboard and jumpers for breadboard version

Step 2: Step 2: Put the LEDs on the Breadboard

In this step, you have to put the LED lights in the right place on the breadboard

The 6 LEDs will be out in Digital pin 2 -7, and six of them should be as near as possible

Make sure you make an extension line on the LED lights by adding two lines and connect the LED on it( see the image). It can be important because, in that way, the LED light can be seen from the outside of the enclosure.

Step 3: Step 3 : Connect the Ultrasonic Sensor

After connecting the LED lights, it is now time to connect the ultrasonic sensor. There are four lines on the sensor, and GND should be connected to GND. Echo should be connected to digital pin number 12. Trig should be connected to digital pin 11. Finally, UCC should be connected to + on the breadboard

Step 4: Step 4: Connect the Speaker

The speaker will then need to be put on the breadboard. You should connect the Digital Pinfor the red line and the other line connects to - .

Step 5: Step 5 : Code

https://create.arduino.cc/editor/bryanlin0318/d6b6...

Just go to this website and download it, you can see it

Step 6: Step 6: Making the Enclosure

There are a lot of ways to do the enclosure. This time, I use my cookie box to make it. First, I make the hole for the USB line son that it can connect to my computer in the side of the box. Then, I made a hole on the top of the box to let my ultrasonic sensor to work. Finally, I make six holes on the top of the box so that my LED lights can be seen at the top of the box. There are still a lot of other ways, and maybe this is not the best, you can discover by yourself!