As we all know that there is a pandemic of COVID-19 all over the world. It is recommended to wash hands at least 20 seconds as a precautionary measure. It is difficult to keep a track while washing hands. So to overcome this difficulty, this device is made.
It is an arduino based project. One ultrasonic sensor is used to detect when a person wants to wash hands. Once ultrasonic sensor detects this, the device starts. A white LED is used to show that the device has started. The countdown for 20 seconds starts now. 4 Red LEDs are used to keep track of time. On every 5 seconds, the LEDs will glow. After every 5 seconds the previously glown LED will turn off and next red LED will glow. When last 5 seconds will be remaining the buzzer will start beeping every second. On completion of 20 seconds the buzzer will blow and will keep on blowing until we again tell the device that we have washed our hands by moving hand in front of ultrasonic sensor.
The implementation of this project is done by assembling all the components over a breadboard. Coding is done using embedded C on Arduino IDE.