#include <Wire.h>
#include <MPU6050.h>

MPU6050 mpu;
//Potentiometer is being used  to simulate the  alcohol sensor (MQ-3)
const int alcoholPin = A0;   
const int buzzerPin = 12;     // Buzzer pin
const int ledPin = 13;        // LED pin
const int threshold_value = 400;    // Alcohol level threshold value

void setup() {
  Serial.begin(9600);
  

  pinMode(buzzerPin, OUTPUT);
  pinMode(ledPin, OUTPUT);
  
  // Initialize the MPU6050 accelerometer placed above the helmet to detect the motion of 
  // the helmet . This is like when we use helmet our head shakes and there will be some movements
  // due to that accelerometer will give record those values and if that value is 
  // higher than the threshold value we say that person wore helmet .
  Wire.begin();
  mpu.initialize();
  if (!mpu.testConnection()) {
    Serial.println("MPU6050 connection failed!");
  } else {
    Serial.println("MPU6050 connected successfully!");
  }
}

void loop() {
  int alcohol_Value = analogRead(alcoholPin);  // Read potentiometer value (simulating alcohol level)
  
  // Get accelerometer data
  int16_t ax, ay, az;
  mpu.getAcceleration(&ax, &ay, &az);
  
  // we are checking the value given by the potentiometer as the value given by alcohol 
  // detector. Basically when the person who has consumed alcohol breathes near the sensor 
  //the value increases significantly from 200 to 800 so we kept threshold value as 400
  //so that if the value greater than 400 says that the person is consumed alchohol 
  // and this sends the message that the rider can not start the bike and this also sends 
  // data to stop the bike to bike sensors provdied in the bike using bluetooth.
  if (alcohol_Value > threshold_value) {
    Serial.println("Alcohol detected! Preventing bike start.");
    digitalWrite(ledPin, HIGH);  // Turn on LED to indicate alcohol detected
    digitalWrite(buzzerPin, HIGH);  // Sound buzzer
    sendBluetoothSignal("Stop");   // Send signal to prevent bike start
    delay(1000);  // Keep the alert for 1 second
  }
  // when the helmet is not worn by the person the accelrometer remains idle and no 
  // movement is detected .That concludes that the person is not wearing helmet and gives 
  // the necessary message that person is not wearing helment and sprevent the bike from starting.
  //similarly when there is a movement in helmet we say we tilt our head or bend our neck
  // down the accelerometer records the value and if that value is greater than threshold
  // value then the person wearing helment and checks for alcohol. if person not consumed 
  // alcohol then we can ride the bike safely.
  else if (abs(ax) < 1000 && abs(ay) < 1000 && abs(az) < 1000) {
    Serial.println("Helmet not worn! Preventing bike start.");
    digitalWrite(ledPin, HIGH);  // Turn on LED to indicate helmet not worn
    digitalWrite(buzzerPin, HIGH);  // Sound buzzer
    sendBluetoothSignal("Stop");   // Send signal to prevent bike start
    delay(1000);  // Keep the alert for 1 second
  } 
  else {
    // If everything is normal, allow bike to start
    Serial.println("Helmet worn and no alcohol detected.");
    digitalWrite(ledPin, LOW);  // Turn off LED
    digitalWrite(buzzerPin, LOW);  // Turn off buzzer
    sendBluetoothSignal("Start");  // Send signal to allow bike start
  }
  delay(250); 
}

// Function to simulate Bluetooth communication via Serial Monitor
// this bluetooth communicates with the bike's electronic control unit and says whether to start the bike or stop it
void sendBluetoothSignal(String command) {
  Serial.println(command);  // Send command to Serial Monitor
}