Introduction:

By taking the help of modern engineering and technology, in this project we are trying to protect the school students as well as the school bus from accidents and undesirable situations. If the bus driver tries to drive the bus after drinking alcohol, the bus engine hesitates to start. This system saves the lives of students in the school bus including the driver. This also supports road safety.

Components required:

1. Battery
2. Relay
3. Resistor
4. Buck converter
5. Diode
6. Charger
7. LED
8. Transistor bc547
9. Switch
10. Buzzer
11. Alcohol sensor
12. Nodemcu
13. LCD
14. Motor

Block Diagram:

Circuit diagram:

Working:

When the bus driver starts the school bus, before that he has to breath near the alcohol sensor to confirm his consciousness test. If he has not drunken alcohol everything goes fine. If he has ethanol in his breath, the sensor detects it. The LCD displays the alcohol value. This condition interrupts the ignition current to reach into the bus engine as a result engine doesn’t start. This saves the lives of entire bus students including the driver.

Advantages:

1. This saves the lives of students in the school bus including the driver.
2. This supports road safety.

Code for Microcontroller:

//Su-Din Technology   Phone-9861004895.
//Interfacing LCD and MQ-3 with Nodemcu.
#include <LiquidCrystal.h>
#define ledPin 15 //Led to Pin D8
const int MQ3 = A0; //sensor to analog pin A0
float sensorValue;
const int rs = D2, en = D3, d4 = D4, d5 = D5, d6 = D6, d7 = D7;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
void setup() {
  Serial.begin(9600);
  lcd.begin(16, 2);
  lcd.setCursor(0,0);
  lcd.print("   Maniabandha  ");
  lcd.setCursor(0,1);
  lcd.print("  High  School  ");
  delay(1000);
  lcd.clear();
  pinMode(ledPin, OUTPUT);
  digitalWrite(ledPin, LOW);
  Serial.println("MQ3 Sensor is Heating...");
  lcd.setCursor(0,0);
  lcd.print("MQ-3 is Heating ");
  delay(20000);
}
void loop() {
  sensorValue = analogRead(MQ3);
  // reading analog input at pin A0
  Serial.println("Sensor Value =   ");
  Serial.println(sensorValue);
  lcd.setCursor(0,0);
  lcd.print("Sensor Value =  ");
  lcd.setCursor(0,1);
  lcd.print("     ");
  lcd.setCursor(5,1);
  lcd.print(sensorValue);
  lcd.setCursor(12,1);
  lcd.print("     ");
  
    if(sensorValue > 950.0){
      digitalWrite(ledPin, HIGH);
      lcd.setCursor(0,0);
      lcd.print("Alcohol Detected"); 
      lcd.setCursor(0,1);
      lcd.print(" Reading > 950  ");
      }
      else{
        digitalWrite(ledPin, LOW);
        }
  delay(2000);
}

Designer:
Er. Anil Kumar Prusty
Phone No. :- 9861004895