Introduction: DIY Hand Washer Timer Machine

Changed from this amazing work by the Tech Lab

What I changed: It is a really fun process and experience while making this machine. Due, I am now a student, meaning that I would have a low spend for this Arduino project, so I had changed the enclosure to a cardboard box that could be found in my house. Also, I have added a speaker to make a noise when you start and finish washing your hands. In order to get a clearer reminder for the user. Next, I changed the format of the machine a little bit by adding visual instructions of how to wash your hands below the led lights that should be helpful to guide the user fro start to end.

During this really intense environment of the COVID-19, I found out it is really important to keep you healthy and always keep in mind your personal hygiene. For example, washing your hand frequently could be the best known effective way to prevent you from getting unknown viruses and bacteria into your body.

However, don't be worried about catching the virus. There are some easy ways that we can fight against this virus. One is to wash our hands, properly. Our hands are the main carrier of all sorts of germs. We frequently touch our eyes, nose, and mouth without even noticing it. When our hands touch these places, we could easily let the virus into our bodies. Overall, washing hands with soap can mostly kill them. But how long should you wash? Would you always lose count of the time? I found out there are a lot of people who think that taking some soap on your hands and without carefully washing them off can be useful for the kill of germs, that's definitely wrong. However, this issue can be proved by giving users a better skill of how to wash your hands properly,

This machine solves this, it gives us a total time of 30 seconds of cleaning your hands thoroughly with directions, this machine would be placed in the restroom. Also, it would automatically detect your hands and starts counting down 30 seconds with each light lighting each 5 seconds for each step. With a beep sound to remind the timer has started.

I know sometimes cleaning your hands every time and multiple times a day can be frustrating and annoying. But this machine can actually create a more creative way and entertain people to wash their hands.


x1 BreadBoard

x1 Arduino Uno

x1 HC-SR04 Ultrasonic Distance Sensor

x1 Red LED Light

1x Speaker

x5 Blue/Green/Yellow LED Lights

Scotch Removable Mounting putty(optional)

a cardboard box (20m x 15m)

a printed sheet of the directions

Step 1: Step 1: How It Works?

I made this project for people who are interested to create his/her own handwashing timer machine themself easily with some supplies that are really easy to get. Not only is it fun to make with children but it is also educational, and definitely useful in the current situation with the COVID-19 virus spreading much more seriously. The main brain of this countdown timer is an "Arduino". It's a tiny computer that can be programmed using personal computers. Arduinos are widely used for learning, prototyping and even actual products. Ardunio gives you space and time to activate your creativity. However, If you don't have any experience with it then don't worry, I will happily walk you through the process easy and I believe that you will be able to get started with Arduino in any second from now on, maybe even make more future projects with it if you like the idea of it.

First, the Arduino is connected to an ultrasonic distance sensor, and 6 LEDs. The Arduino is sending ultrasonic sound waves with the distance sensor and checking the time it takes for the sound waves to be reflected back to the sensor. Using the time, it measures the distance of anything right in front of it. So the Arduino is always reading the sensor, waiting for your hand to appear within 20 centimeters. As soon as it detects something within 20 centimeters, the Arduino turns on the red LED and waits for 4 seconds for you to let you prepare yourself. Such as, rolling up your sleeves, etc. Then it starts the 30 seconds countdown. Eventually, the 5 blue LEDs light up, one by one, over a period of 30 seconds. Once the all the lights had disappeared, you will able to get clean, safe hands as the result.

Step 2: Step 2: Make the BreadBoard Version

Making this project on the breadboard is really simple. You will just have to connect our Arduino to the sensor, the 6 LEDs, and the speaker. You can follow the picture provided above that shows how to hook things up with Arduino Uno, We use jumper wires to connect everything together. Don't forget to check the LED polarities. The longer pin is usually the positive pin, so the longer pins should be connected to the Arduino digital pins.(numbered ones) The shorter pins, on the other hand, should be connected to ground (GND) pin of the Arduino, usually the (-) one. To make it leave the breadboard in order to attach it to the box. It is better to attach them with longer jumper wires both required to connect the LED polarities.

Step 3: Step 3: Upload the Code (nearly There:)

Once we are done building the circuit, it's time to upload the code to the Arduino board. You will have to install the Arduino IDE (Integrated Development Environment) onto your computer or notebook. Then download the code attached below in this step. I have written many comments in the code to make it easy to understand for newbies.

Now connect the Arduino to your computer with the cable that came with it. Open the code on your computer using the Arduino IDE. From Tools > Board, select the Arduino that you're using. For me, it was an Arduino Leonardo. Also, select the port for your Arduino from Tools > Port. Next, click the Upload button on the top left corner. The upload should begin. You should get a "Done Uploading" message once it's complete. If you get an error while uploading, make sure you chose the right board and port. Try a different port until it works. You might also need to change processor if you are using an old Arduino Nano, you can find the option in Tools > Processor.

Step 4: Step 4: Testing If It Works!

Once you have successfully uploaded the code, it's time to check if the timer works correctly before putting it into an enclosure. Normally all the LED should be off. Take your hand in front of the sensor, the red LED should turn on. Eventually, the remaining blue LEDs should turn on with 5 seconds interval, until the 30 timer ends.

If it does. Congratulations! Your timer works! Hooray! If everything doesn't work normally, first check your connections to the ultrasonic sensor, and the speaker. It's easy to mistakenly connect the sensor pins reversed. If an LED doesn't light up, check it's connection and polarity. If it still doesn't work, try replacing the LED.

After that, you can cut holes on the cardboard to fit the LED in and the sensor in. Also, you can be creative on the cover of the machine. You can create your own kind of machine with different drawings. It is fun and creative to make, as a result, you can also learn something new and the importance of washing your hands.