My name is Santosh, I have made a hand wash timer using Arduino. The purpose is to help to remind ourselves to wash our hands for at least 20 seconds. We’re calling the project Go Corona, and I’m sharing the tutorial so that anyone can make it by themselves. This project is for everyone.
WHO recommends to wash our hands with soap for at least 20 seconds. But it is difficult to trace the time during washing hands. So, here I have come with this Non-Contact Hand Washing Timer.
Benefits of Hand Wash Timer (Go corona)
- The entire system is automated and contactless.
- Instantly ready for the second user.
- Requires minimum cost.
|SG-90 Micro Servo
|HC-SR04 Ultrasonic Sensor
Wire up the sensor and servo according to the wiring diagram attached below.
VCC -> 5V on the Arduino
Trig -> Pin 9 on the Arduino
Echo -> Pin 10 on the Arduino
GND -> GND on the Arduino
For the Servo Motor, use the Male\Male wires to connect the following-
Red Servo Wire (5V) -> Vin on the Arduino
Black Servo Wire (GND) -> GND on the Arduino
Orange Servo Wire (Signal) -> Pin 7 on the Arduino
Assemble the Timer
And cut out a servo sized hole
Note: You can also check out the video for a step-by-step wiring guide.
Open the Arduino software
Make sure to install the NewPing, EWMA, and Queue libraries from the Arduino library manager before running to the sketch!
Alright, it’s time to get your hands washed! Place your Go Corona to the sink and tape the ultrasonic sensor around the rim.
The ultrasonic sensor works by sending out ultrasonic sound waves and measuring how long it takes for them to return. If the sensor is receiving reflections from things that aren’t hands in the sink, it may trigger the timer unnecessarily.
Warning: Electronics and water don’t mix! So, think about the location of your Arduino.
Once the sensor is in a good position, plug the Arduino into a USB wall adapter nearby. The servo should sweep back and forth, indicating the timer is active.
Try washing your hands and see if the countdown starts, then its working well.