// Q2 write a program for the computation of your BMI (Body mass index):
// bmi = body mass/ body height

// conditions
// 1. body mass can be taken as a serial input
// 2. height can be computed through an appropriate sensor.
// 3. display bmi on lcd. 

#include <Wire.h>
#include <LiquidCrystal_I2C.h>

#define TRIG_PIN 9 
#define ECHO_PIN 10 

LiquidCrystal_I2C lcd(0x27, 16, 2); 

float bodyMass = 0;    
float height = 0;      
float bmi = 0;         

void setup() {
  Serial.begin(9600);          
  lcd.begin(16, 2);             
  lcd.backlight();              

  pinMode(TRIG_PIN, OUTPUT);    
  pinMode(ECHO_PIN, INPUT);     

  lcd.setCursor(0, 0);
  lcd.print("Enter mass:");
}

void loop() {
  if (Serial.available() > 0) {
    bodyMass = Serial.parseFloat(); 
    Serial.println("Mass received.");
    
    
    height = measureHeight();
    bmi = computeBMI(bodyMass, height);

    
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("BMI: ");
    lcd.print(bmi);
    lcd.setCursor(0, 1);
    lcd.print("Mass: ");
    lcd.print(bodyMass);
    lcd.print(" kg");
    delay(2000);  
  }
}


float measureHeight() {
  long duration;
  float distanceMeters;


  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);

  
  duration = pulseIn(ECHO_PIN, HIGH);

  
  distanceMeters = (duration * 0.0343) / 2 / 100;
  return distanceMeters;
}

float computeBMI(float mass, float height) {
  if (height > 0) {
    return mass / (height * height);
  } else {
    return 0;
  }
}