Published July 25, 2020

Automatic Hand-wash / Sanitizer Dispenser - Peristaltic pump

This device detects the presence of your hand and automatically release a specific amount of Hand-wash / Sanitizer to your hand.

BeginnerWork in progress4 hours30,413

Automatic Hand-wash / Sanitizer Dispenser - Peristaltic pump

Things used in this project

Hardware components

Arduino UNO

Peristaltic Pump 12 V

Ultrasonic Sensor - HC-SR04 (Generic)

BC 547 NPN Transistor

1N4007 – High Voltage, High Current Rated Diode

Jumper wires (generic)

Hook Up Wire Kit, 18 AWG

12 V 1 A Adapter

Software apps and online services

Arduino IDE

Autodesk Tinkercad

Hand tools and fabrication machines

Hot glue gun (generic)

Soldering iron (generic)

Story

This device is an automatic hand wash dispenser which dispenses a specific amount of handwashing liquid on to your hands when placed under a distance measuring sensor(ultrasonic sensor).

Here the ultrasonic sensor is used to detect the presence of hand placed under the device ( 20 cm from the sensor).

A 12 V Peristaltic pump is employed to eject the right amount of liquid at the right time. i.e. when the hands are placed in the 20 cm range.

The Arduino UNO board controls the pump based on the distance obtained from the ultrasonic sensor.

The peristaltic pump is controlled via NPN Transistor (BC 547), a flyback diode (IN4007) is connected in parallel with the motor. The diode protects the Arduino from the back emf produced by the pump.

An adapter (12 V 1 A DC Output) is used to power the Arduino, which in turn controls the 12 V Pump.

Make sure the U. S. sensor is placed just above the outlet of the peristaltic pump so that it can detect the hands kept under the outlet.

The code given below can be modified to obtain the required amount of liquid, the details regarding this are given in the code.

Put the inlet tube of the pump inside the solution which is to be dispensed.

ENJOY!

Code

Code

#define echoPin 4                // defining pins and variables
#define trigPin 5
int long duration;
int distance;

const int motor= 10;             // pin connected to base of npn transistor

void setup()
{
  pinMode(echoPin,INPUT);        // defining pin modes
  pinMode(trigPin,OUTPUT);  
  pinMode(motor, OUTPUT);        
}

void loop()
{
  digitalWrite(trigPin,LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin,HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin,LOW);
  duration=pulseIn(echoPin,HIGH);
  distance=(duration*0.034/2);   // now you got the distance 

  if(distance<=20)               // checking the presence of hands in 20 cm limit
  {  
    digitalWrite(motor,HIGH);    // if present motor operates for some time
    delay(4000);                  // delay value to changes the operating time
    digitalWrite(motor,LOW);     // pump stop working for some time
    delay(1000);                 // some delay prevents continous operation
  }
  else 
  {
    digitalWrite(motor,LOW);     // if no hands detected - no operation
  }
}

Credits

Sartaj S B

1 project • 5 followers

Automatic Hand-wash / Sanitizer Dispenser - Peristaltic pump

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

Schematics

Circuit Diagram

Code

Code

Credits

Sartaj S B

Comments

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Automatic Hand-wash / Sanitizer Dispenser - Peristaltic pump

Automatic Hand-wash / Sanitizer Dispenser - Peristaltic pump

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

Schematics

Circuit Diagram

Code

Code

Credits

Sartaj S B

Comments

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