Published August 12, 2020 © GPL3+

Touch-less Hand Sanitizer

With the pandemic COVID-19, the world started to review its habits. This project presents a touch less hand sanitizer to support us!

BeginnerFull instructions provided20 hours6,462

Things used in this project

Hardware components

Arduino Nano R3

Arduino Relay Shield

Rotary potentiometer (generic)

Mini Alcohol Water/Gel Pump

Optical Sensor TCRT5000

Software apps and online services

Arduino IDE

Hand tools and fabrication machines

Plastic Hose

Locksmiths

Story

Why this project

In Brazil, one of the requirements to reopen the business after social distance decisions is to provide hand sanitizer on the entrance of stores.

Normally, this task is performed by an employee applying the sanitizer on each customer`s hands.

This project support business to comply with the legal requirements for reopening and unburden the company due to not requiring to relocate an employee from its normal tasks to do this robotic task.

Our solution provides an automatic device to support the reopening of business and the mitigation of COVID-19 spread.

Prototype / Testing

One of the customization required for correct operation of our solution is the possibility to configure how long the pump will operate to spill the hand sanitizer.

To comply with this customization without software updates, the approach is to use a potentiometer that allows the owner to configure the quantity according with the hand sanitizer density (liquid/gel) and with the remaining quantity on the alcohol resevoir.

Testing Arduino Nano with Relay, Potentiometer and Proximity Sensor

The pump was tested to confirm that its performance is enough to work with the hand sanitizer:

Pump working with Hand Sanitizer

Assembly

On the rear side, all the harware is mounted with:

Power Supply
Arduino Nano
Relay Shield
Pump
Proximity Sensor
Potentiometer
Hand Sanitizer Resevoir

The rear side of the product contains all hardware and the hand sanitizer resevoir (structure)

Final Product

The front side of the product allows customization according to the customer request, so it can presents some messages and the company logo.

Front of the product

Rear of the product (Assembly with Arduino Nano)

Sensor Test and Timer Configuration (Potentiometer)

Code

Arduino Source code

int pinRelay = 7;
int pinSensor = 5;
int pin5v = 3;
int pin5vPOT = 4;
int pinGndPOT = 6;
int pinPOT = A5;
int output_action = HIGH;
int value = 0;

 
void setup(){
    pinMode(pinRelay, OUTPUT);
    pinMode(pinSensor, INPUT);
    pinMode(pin5v, OUTPUT);
    pinMode(pin5vPOT, OUTPUT);
    pinMode(pinGndPOT, OUTPUT);
    pinMode(pinPOT, INPUT);
    digitalWrite(pinRelay, HIGH);
    digitalWrite(pin5v, HIGH);
    digitalWrite(pin5vPOT, HIGH);
    digitalWrite(pinGndPOT, LOW);
    
}
 
void loop(){
    output_action = digitalRead(pinSensor);
    value = analogRead(pinPOT);
 
    if (output_action == HIGH){ // if the sensor do not detect something close
        digitalWrite(pinRelay, HIGH); //the relay is open
    } else { //otherwise, sensor senses a hand close
        delay(500);
        digitalWrite(pinRelay, LOW); //activate the relay
        delay(value*2); // delay 
        digitalWrite(pinRelay, HIGH); //deactivate the relay
        delay(2*1000); // delay 
    }
}

Credits

Gustavo Bertoli

3 projects • 8 followers

gabriel123br

0 projects • 1 follower

Touch-less Hand Sanitizer