This arduino project will guide you how to make an Automatic alcohol dispenser.


This arduino project will guide you how to make an Automatic alcohol dispenser. User no need touch anything to get alcohol, just come near ultrasonic sensor, alcohol will be pushed out, then an audio file will be played to inform to user should keep hand to be cleaned, meanwhile the OLED screen will display "THANK YOU!"

I hope this project will help Arduino fan can make your own an automatic alcohol dispenser to keep clean your hand in the time of fighting with COVID19

See full instruction video here

https://www.youtube.com/watch?v=Hw5sJ9Llglw

Step 1: Part List

Component for the project:

1. Arduino UNO https://amzn.to/2P58O7s

2. SD card module https://amzn.to/2E1myhb

3. SD card 8GB https://amzn.to/2xTCz6i

4. Amplifier PAM8403 & speaker https://amzn.to/2V2uWC9

5. Ultrasonic sensor HC-SR04 https://amzn.to/2rRrRa5

6. OLED 128x64 https://amzn.to/31Vwikq

7. Breadboard cables https://amzn.to/3ae8vk0

10. MDF wood 3mm thickness (laser cut) https://amzn.to/33Q4LTz

11.White glue (for MDF wood) https://amzn.to/2WKo7YJ

Step 2: Make the Case and Install PCB Parts

I used MDF 3mm wood to make the case for this project. MDF wood is cut by laser cnc machine, design file is at this link https://bit.ly/2XuECIy

In case you don't have laser cnc machine, you can cut it by jig saw.

Then the case is fixed by white glue.

After finish the case, we will install electronics parts like Ultrasonic sensor, OLED 128*64, Arduino UNO, H-bridge, SD-card module

Step 3: Circuit Desgin and Do Wiring

Circuit design

Let's make a circuit like picture, then do wiring by breadboard cables. I notice that some breadboard cables has low quality, it can be broken inside, then it leads me a lot of troubleshooting time. I recommend you check the breadboard cable before do wiring

Step 4: Install the Pump

Mini pump 5VDC

The pump is mini type, 5VDC power supply (its power also small). The pipe is connected to pump, then all of them is put into a bottle.

This project is used alcohol for cleaning hand. Some of my friends tell me that alcohol is easy catch fire! At beginning of project, i didn't notice about this hahaha :D

Anyway, we can replace by another type of soap liquid, right?

Step 5: Make the Nozzle

Old pen

The nozzle is used from old pen. Fortunately, it is perfect suitable to the pipe, what a lucky!

Then install every thing on the case, look lovely, right :) ?

Step 6: The Code Works

The code works is not so difficult for me, take about 1 hour to finish.

The code can be downloaded here https://bit.ly/2XuECIy

Function of the code as following:

1. Detect hand (obstacle) near ultrasonic sensor

2. It will push out alcohol (delay time 800ms)

2a. Meanwhile, it will say "Thank you, please keep your hand to be cleaned!"

How it sound? Arduino will take out audio file from SD card for play. I record my voice from my phone, then convert it into mono type, 8bit, 11025Hz at this online tool https://audio.online-convert.com/convert-to-wav

2b. OLED screen will show "THANK YOU"

3. After finish, it will wait for another one with OLED screen word "Please keep hand CLEAN"

I hope this project will help everybody in time of COVID19.

Please keep healthy, and the hard time will pass :)

engineer 2you
I'm an electrical engineer who loves making DIY project with Arduino, Raspberry. Meet me at Youtube/c/engineer2you :)