Introduction: Hand Wash Timer; Cleaner Version

Not only the Corona Virus needs to be prevented, but all diseases. According to the Centres for disease and prevention, there are 2.8 millions of infection and 35000 deaths due to bacteria and fungi. This shows that people should wash their hands constantly even without the Corona Virus outbreak. One day, I was scrolling trough the intractable website. Then I read an intractable about a simple hand wash timer project. I thought to myself, is washing hands for 20sec enough to clean the virus? Therefore I modify this machine into a 30 seconds hand washing timer, so the hands can be totally clean. This project is inspired and based on "The Tech Guy" who did a hand wash timer project. ( Click to take a look of his project: Here)


To do this project, you will need:

Red Led x 1

Blue Led x 4

Green Led x 1

Electric Resistance for Led bulb x 6

Jump Wire x18

Extension wire with receiver head on one side x 12

Ultrasonic distance sensor x 1

Arduino Uno, Leonardo x 1

Breadboard x 1

A container for the timer x 1

Step 1: How Does the Machine Work?

If you see this website, you probably know how does Arduino work. Therefore, I will not explain how that works. .

This hand wash machine is using a sensor and six Led lights that will lit up every six seconds. When the sensor detects the washer, the count down will start. The red light will lit up first. Before the next blue light lit up, the washer should use the time given to get their hands wet and get their soap ready. When the first blue light lit up, the washer should start washing their hands. Then after 30 seconds of washing, all the blue lights will be lit up. Then it's the green Led light. When the green light lit up, the washer should perform the last step, which is to wash the soap off. Finally, the washer's hand will be clean with no germs.

Step 2: Connecting the Materials on to the Breadboard.

You will have to connect two main materials: Ultrasonic distance Sensor and LED lights. First, the LED light bulb. There are two connector leg on a LED bulb. The longer leg is for connecting to the D-pin, and the shorter leg is used to connect to negative ground cable using jump cable. Between the negative connection cable and the lightbulb cable need to have an electric resistant in the middle to avoid electric overload on the bulb and blow up the bulb. If you want to place the light bulb on to the box, it is better to connect the legs of the light bulb to a cable with receiver on the one side. So the light bulb don't need to stick on to the board. After you finish connect all of the bulbs, you need to connect the Ultrasonic distance sensor onto the board. On an Ultrasonic distance sensor, there are four legs. The four legs are positive, Trig, Echo, and negative. Positive leg needs to be connected to 5V plug through jump cable. The Trig and Echo needs to be connected to the D-pins. Finally, the negative needs to be connected to the ground negative plug. But this one don't need an electric resister in the middle. After all the cable work, you are good to go to the next step.

Step 3: The Code.

This step is like giving this project a soul. Now, download the code of this project and upload to your Arduino code editor. Then, connect the board to your computer. After, you're ready to press the upload. Remember, you need to choose the right port to upload. To choose the port, go to tools. You need to choose the right board type and the right port.

You can get the code: Here

Step 4: Packaging

If you have the container for the timer, good! You should drill holes and stick your led light bulbs through it. Also, you need to drill holes on the top of the container so the sensor can be on the top. Understand that the package can be any kinds of form. It doesn't have to be a box. Also, be-careful that the led light bulbs might fall out easily, so it's better to have pieces of sticky mud to hold the bulb.

Step 5: Testing It Out!

Finally, after all these hard work we can test the result. After uploading to code up to the board. All you need is a portable charger or a battery to make it work. Now place your hand washing timer beside the sink and activate the machine. If you have a box, you can hide the battery inside the box. If not then be ware that water might spill on to your board when you wash your hand. If the machine fits the description at the start, then you are good to go!

Step 6: Conclusion and Reference.

This machine can make washing hands interesting, and also make sure that people can wash their hands clean enough. I hope that after this pandemic, people can be more aware that cleaning their hands is essential to our life. Not only it will prevent you from illness, it will also keep your surroundings clean. Therefore, if you made this project, it's the best to keep the project so it can remind you to wash your hands every time you walk pass the sink.

Again, this project is inspired by The tech lab. Please check their websites if you are interested in crafting Arduino projects. Also, pictures and technical knowledge in this project are supported by Mr. David Huang. (Click for Mr. David's website. And click here for his youtube channel)

Have fun!