Introduction: 20 Second Hand Washing Timer for COVID-19

As the global COVID-19 spread, we should protect ourself not only by gathering less and wearing face mask, but also washing hand more often.

It ’s not effective against viruses if you don’t wash your hands properly.

How to wash our hands correctly? We should use hand soap, and washing 20 seconds at least. But how to ensure we have washed for 20s? So I made this 20 Second Hand Washing Timer for COVID-19. You can easily know the time and when time countdown is started and ended, the buzzer will remind you with beeps.

We should protect ourselves in this special period.

Step 1: Suppliers

Collect all the components you will use in this project.

I used the following components, for your reference:



uPyCraft V1.1

Step 2: Wire the Electronics Components

Next, wire up the electronics components according to my wiring diagram.

HC-SR04----MakePython ESP32

  • VCC → 3.3V
  • Trig → IO13
  • Echo → IO12

Buzzer----MakePython ESP32

  • VCC → 3.3V
  • O/I →IO15
  • GND → GND

Step 3: Program and Test

All the component and circuit is ready, then flash the codes. You can download here.

Step 4: Install the Timer to Your Sink

Ok, it is time for washing! Install the timer to your washing sink.


1. You should adjust the appropriate measuring distance of HC-SR04, according to the condition of your sink.

2. Pls be aware to protect the electronics from humidity and direct contact with water💧.

Step 5: Complete and Wash Your Hands

Let's wash our hands for 20s and protect ourselves from the coronavirus!

Step 6: Other Display Solutions

As the Python is a simple and easy-to-learn programming language, you can program by yourself to realize more creative and beautiful displays for the countdown animation.

As we can see there's also the MakePython ESP32 Color LCD which is very interesting, with colorful LCD display, so those boards are limited only by your imagination!