#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 16, 2);
const int trigPin = 7;
const int echoPin = 6;

class MHRatio {
  private:
    float weight;
    float height;

  public:
    MHRatio(float w, float h) : weight(w), height(h) {}

    float calculateRatio() {
      return weight / (height * height);
    }

    void displayRatio(float mhratio) {
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("MHRatio: ");
      lcd.print(mhratio, 2);
    }
};

float measureHeight() {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  long duration = pulseIn(echoPin, HIGH);
  float distance = duration * 0.034 / 2;

  return distance / 100.0;
}

void setup() {
  Serial.begin(9600);
  Serial.println("Enter Weight:");

  lcd.begin(16, 2);
  lcd.backlight();

  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);

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


void loop() {
  if (Serial.available() > 0) {
    float weight = Serial.parseFloat();
    float height = measureHeight();

    if (weight > 0 && height > 0) {
      MHRatio stoneRatio(weight, height);
      float mhRatio = stoneRatio.calculateRatio();
      stoneRatio.displayRatio(mhRatio);
    }
  }
}