Table of Contents
1.0 INTRODUCTION TO THE PROBLEM3
1.1 Effect of Good Hand Hygiene Practices through AHD
2.0 THE GRAND SOLUTION4
2.1 How did we design an Automatic Hand Sanitizer Dispenser? 4
2.2 Materials Required 5
2.3 How it technically works 6
2.4 Design Features Summary 7
2.5 Circuit Diagram 7
2.6 The code behind the magic 8
3.0 CONCLUSION1
1.0 INTRODUCTION TO THE PROBLEM
Corona Virus (COVID-19) is wreaking havoc in the world. Almost every country is suffering from the Corona Virus. WHO has already announced it a Pandemic disease and many cities are under lockdown situations and changed our lifestyle. In this current scenario of the global outbreak, it is advised by WHO (world health organization) to maintain Healthy Hand Wash and Sanitation Habits, but the main problem is the way we do it, that is by physical touch. What if someone who is not infected with Covid-19 touches the hand sanitizer previously used by the COVID-19 infected person? This action will also infect a normal person.
Walk into any store these days and you’ll almost always see an employee holding up a thermal gun and dispensing sanitizer, It doesn’t take more than a second of thought to realize how ineffective this system is, not just turning a resource (an employee) into a glorified dispenser but also slowing down the rate of people entering the store leading to potential pileups outside, making social distancing something impossible to enforce.
So how will you protect your apartment, your hospitals, your supermarkets? The answer to these questions is the use of an efficient, effective, economic hand sanitizer dispenser.
Looking at this dire situation the team came up with an idea to use arduino and raspberry pi to make an three stage dispenser. The fundamental part of the circuit is the dispenser which uses a DC servo motor to dispense the hand sanitizer and sound an alarm when the person can move on. This simple dispenser eventually evolved into something a bit more complex.
The Automatic dispenser.
1.1 Effect of Good Hand Hygiene Practices through AHD
Analysis of the impact of hand-hygiene interventions for reducing infectious illnesses in the community is important for several reasons.
1 First, there has been an explosion in the options and use of hand-hygiene products in the community.
2 Second, hand hygiene is considered an important intervention measure for pandemic public health threats, such as severe acute respiratory syndrome and avian influenza.
3 Third, research has suggested that there may be risks, including the emergence of antibiotic-resistant bacteria, associated with the use of some hand-hygiene products such as antibiotic sanitizers.
As important as everyone’s hands are in doing work, they also equally contribute to the transmission of many disease-causing pathogens. The fact that most facilities such as toilets, bathrooms, and even eating places are shared with people means that there are great chances of disease transmission among the everyone, and even with good cleaning, personal hygiene is important. This can be addressed by having automatic hand sanitizer dispensers in a lot of places, as they have far reaching benefits which may include the following:
Improved Hygiene
Automated dispensers used in providing sanitizers to workers or public are the best option. Unlike manually operated types that require direct contact every time a person needs to use it, there is no contact with automated dispensers. This prevents or decreases the chances of disease-causing pathogens passing from one person to the other. In the long run, there will be a decline in infections among the people, which is likely to increase productivity.
Encourages Usability
With an automated sanitizer dispenser in public places, many people are likely take the time to keep their hands clean. This is not true with a manually operated dispenser; because many consider it to be tedious and therefore tend to avoid it. A touch-free sanitizer dispenser encourages use and increases the number of people who clean their hands, and this will reduce the number of transmissions of infections among others.
It Is Enjoyable
Automated soap dispensers are fun to use, luring even those who would not usually clean their hands to use it, and in the process, the level of transmission of pathogens will decline significantly. In the long run, productivity will be enhanced.
Economical
With sanitizer dispensers, the amount of sanitizer that is dispensed is the same every time, unlike manually operated types where there is no uniformity. Because of this, sanitizer which could otherwise be used for a day can be used for two to three days with sanitizer dispensers. This is likely to increase revenues and profits of the company in the long run.
2.0 THE GRAND SOLUTION
2.1 How did we design an Automatic Hand Sanitizer Dispenser?
In the above picture, you can see a normal hand sanitizer and to operate this hand-sanitizer, we have to apply pressure on it and when we apply pressure on it, it creates pressure on the liquid in the bottle and when the pressure is released, hand sanitizing liquid will be pumped out.
So this was the basic introduction to the work of general hand sanitizer, now we used this logic and applied it in the design of automatic hand sanitizer dispenser.
To design an automatic hand sanitizer dispenser, first, we need a container to store soapy water. After that, we will need something that will pump soap water and this thing is a DC water pump.
The DC water pump will pump out soapy water for us. But what is it that will trigger the water pump? The answer to this question is as follows.
Distance Sensor For Automatic Hand Sanitizer DispenserThere are different types of sensors available in the market for distance sensing but for this project, we will use one of the following two sensors.
· Ultrasonic Sensor for Automatic Hand Sanitizer DispenserThe ultrasonic sensor uses ultrasonic sound waves to detect the object. The transmitter of the sensor transmits ultrasonic waves and the receiver of the module receives those ultrasonic waves.
· Interfacing Ultrasonic with ArduinoThe following figure shows the interface of the ultrasonic sensor with the Arduino. In this, we have connected the trigger pin of the ultrasonic sensor to the D3 of the Arduino board and the D2 pin of the Arduino to the echo pin of the ultrasonic sensor.
2.2 Materials Required
· Interface L298N DC Motor Driver Module with Arduino
· Power supply
· HCSR04
· Camera module
· Motor
· Connecting Wires
2.3 How it technically works
An Arduino nano controls the Automatic Sanitiser Dispenser which is triggered by an HC-SR04 Ultrasonic sensor upon detecting the hand under the sanitiser pump. An stepper motor is used to push the pump by utilizing a lever mechanism and dispense the sanitiser. The design can be mounted on the most common sanitiser pump in the market making it easy to re-fill or change the sanitiser bottle.
The Concept behind the Automatic Sanitizer Dispenser is very simple. We have used an HCSR04 Ultrasonic Sensor to check if any object such that the glass is placed before the dispenser. A solenoid valve will be used to control the flow of water, which is when energized the water will flow out, and when re-energized the water will be stopped. So we will write an Arduino program which always checks if any object is placed near the tap, if yes then the solenoid will be turned on and wait till the object is removed, once the object is removed the solenoid will turn off automatically, thus closing the supply of water.
The ultrasonic sensor uses ultrasonic sound waves to detect the object. The transmitter of the sensor transmits ultrasonic waves and the receiver of the module receives those ultrasonic waves.
The solenoid valve used in this project is a 12V valve with a maximum current rating of 1.2A and a continuous current rating of 700mA. That is when the Valve is turned on it will consume about 700mA to keep the valve turned on. As we know an Arduino is a Development board that operates with 5V and hence we need a switching driver circuit for the Solenoid to turn it on and off.
The switching device used in this project is the IRF540N N-Channel MOSFET. It has the 3 pins Gate, Source and Drain from pin 1 respectively. The positive terminal of the solenoid is powered with the Vin pin of the Arduino. Because we will use a 12V adapter to power the Arduino and thus the Vin pin will output 12V which can be used to control the Solenoid.
The Ultrasonic Sensor is powered by the +5V and ground pins of the Arduino. The Echo and Trigger pin is connected to pin 8 and pin 9 respectively. We can then program the Arduino to use the Ultrasonic sensor to measure the distance.
The sensor can be installed above the sanitiser dispenser looking down or next to the sanitiser dispenser looking up. It reacts within a range of 10 – 30 cm and activates the servo motor via the Arduino. The servo motor pulls on a string that runs over the pump of the sanitiser dispenser and is fixed on the other side. This pushes the pump down and sanitiser is dispensed. Afterwards the servo moves back to its starting position, the pump moves up again.
To ensure the function you have to adjust three values in the code. To do this, build up the circuit and do a dry test without sanitiser dispenser. Load the code on the Arduino board and start the serial monitor of the Arduino software
2.4 Design Features Summary
· Touch-less, automatic sanitiser dispensing operation of the pump triggered by an ultra sonic sensor.
· Use of a LED indicator to prompt the user to continue applying sanitiser on his/her hands for 20 seconds rubbing them thoroughly before starting to wash with water, as the World Health Organisation recommends.
· Ability to mount on the most common sanitiser pump in the market to allow for easy bottle refill/exchange.
· Use of 3D printable materials and design geometry that allows users to replicate the design locally.
· Use of cost effective electronics and motors as is the arduino nano or the SG90 servo motor.
· Device is power grid independent using the most common AA type batteries.
2.5 Circuit Diagram
2.6 The code behind the magic
How this dispenser works is:
1. The arduino IDE is run on the raspberry Pi, thus allowing the Raspberry Pi to communicate with the Arduino, This is achieved by adding a few extra lines of code in the arduino IDE and in python, The codes are given below:
char receivedChar;
boolean newData = false;
void setup() {
Serial.begin(9600);
#specify the pinmodes here
}
void loop() {
recvInfo();#To receive data from the raspberry pi
}
void recvInfo() {
if (Serial.available() > 0) {
receivedChar = Serial.read();
newData = true;
}
}
while(newData == true) {
#What the arduino will do after it gets the data it needs from the raspberry pi
newData = false;
}
}
We enter the following code to set up serial communication between the Arduino and Raspberry. Go to the Desktop and open the IDLE application, and type in the code there.
import serial
ser = serial.Serial('/dev/ttyACM0', 9600)
2.Once the raspberry pi and Arduino have been connected, The raspberry PI runs the python script detect_mask_video.py, which is essentially a Face Mask Detector using Keras, Tensorflow, MobileNet and OpenCV where the raspberry pi camera module is used to detect the mask.
The code in action:
The resultant plot after training our code with our dataset of people wearing masks and not wearing masks.
Once the algorithm detects a mask, It stores a value 1 in a variable flag, else flag value is 0.Using Step 1, the code sends this flag value to the arduino.
3.Once the user has been successfully detected to be wearing a mask, the arduino triggers the ultrasonic (HC-SR04) component to send a Pulse to detect if the person’s hands are in front of the sanitizer dispenser, The major principle here being Echolocation to locate objects by bouncing sound waves off of them, and then measuring the time taken for an echo to return, and calculating the direction the echo came from..
#include<servo.h>
#define echoPin 8;
#define trigPin 9;
#define Relay 8;
#define Door 4
char receivedChar;
boolean newData = false;
int long pulseTime;
int distance;
int val;
void setup() {
pinMode(trigPin, OUTPUT);
pinMode(echo, INPUT);
pinMode(Relay, OUTPUT);
pinMode(Door, OUTPUT);
Serial.begin(9600)
}
void loop() {
digitalWrite(trigPin, LOW);
delayMicroseconds(10);
digitalWrite(trigPin, HIGH);
delayMicroseconds(20);
digitalWrite(trigPin, LOW);
val=analogRead(A5)
if(val == '1'){
duration = pulseIn(echoPin, HIGH);
distance = (duration/2) * (331.3/10000);
Serial.println(distance);
if(distance>1 && distance<10){
digitalWrite(Relay, HIGH);
}else{
digitalWrite(Relay, LOW);
}
delay(5000);
digitalWrite(Door, HIGH)
delay(20000)
digitalWrite(Door, LOW)
}
4.Once the sanitizer has been dispensed, Finally the last Servo motor gets activated opening the barrier preventing the person from entering thus moving onto the next person.
The barrier is pictured below, with the Dispense being placed near the barrier and the barrier is operated by a 12V DC servo motor.
3.0 ConclusionThe system surely help in implementing the hand hygiene without any challenges as it is a must to sanitizer if you are to access any
entry point. It is much safer and more recommended due to its touch less property which zeros down any chances for cross contamination. This is a low cost user friendly system that anyone can make use of. All the devices communicate well. It can be
concluded here that the system has been successfully implemented and the aim is achieved without any deviations. The results
achieved in this project are genuine and are a product of sincerity and hard work.
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