#include "DHT.h" 
#define DHTPIN 2        
#define DHTTYPE DHT22   
DHT dht(DHTPIN, DHTTYPE);

#include <Wire.h>
#include <LiquidCrystal_I2C.h> 
LiquidCrystal_I2C lcd(0x27, 16, 2);

#include <Servo.h>
Servo servo;  
#define servo1 3 

int buzzer = 4; 
 float h,t,f;
 float inductiveVal;
 float thickVal;

const int analogPin = A0;
const int samples = 8;        // moving average samples (power of two)
int buffer[samples];
int idx = 0;

float calib_a = 0.005; // slope (mm per ADC unit) -- example placeholder
float calib_b = -2.0;  // intercept (mm)



#define trig 8
#define echo 9

  long duration, distance;
 float layo,thickness;
 

void setup() {
  Serial.begin(9600);
  dht.begin();
  servo.attach(servo1);
  servo.write(0); 
  Serial.println("DHT22 Reading...");

  lcd.init();       // Initialize LCD
  lcd.backlight();  // Turn on backlight
  lcd.setCursor(0, 0);
  lcd.print("  Welcome To");

  lcd.setCursor(0, 1);
  lcd.print("AutomaticWelding");
  delay(5000);

  pinMode(buzzer, OUTPUT); 
  buzzMe(2);
 
  Serial.println("DHT22 Reading...");
  
  pinMode(trig, OUTPUT);
  pinMode(echo, INPUT);
 
   
}

void loop() { 
//testDevice();

getTemp(); 
detectThickness(); 
 
//Conditions
if (thickVal <=0 ) { 
 servo.write(0);  
} else if (thickVal >= 1 && thickVal <= 3) {
 servo.write(120);  
}else if (thickVal >= 4 && thickVal <= 5) { 
   servo.write(140);  
}else if (thickVal >= 6 && thickVal <= 8) { 
   servo.write(160);  
}else if (thickVal >= 9 && thickVal <= 10) { 
   servo.write(180);  
 }else  { 
   servo.write(0);  
}
 
displayLCD();


}
 
 
void detectThickness(){  
  digitalWrite(trig, LOW);
  delayMicroseconds(2);
  digitalWrite(trig, HIGH);
  delayMicroseconds(10);
  digitalWrite(trig, LOW); 
  // read echo
  duration = pulseIn(echo, HIGH); 
  // convert to distance (cm)
  distance = duration * 0.034 / 2;

  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");

  thickVal  = 10 -  distance  ;
  if(thickVal >= 50 || thickVal <=0 ){
    thickVal = 0;
  }
  delay(200);
 
}
 



/// =========================================================

void buzzMe(int x){ 
  for (int i = 1; i <= x; i++) {
    digitalWrite(buzzer, HIGH); // turn ON
    delay(500);
    digitalWrite(buzzer, LOW);  // turn OFF
    delay(500);
  }
}
    
  
void getTemp(){
    h = dht.readHumidity();
    t = dht.readTemperature();      // Celsius
    f = dht.readTemperature(true);  // Fahrenheit

  // Check if readings are valid
  if (isnan(h) || isnan(t)) {
    Serial.println("Failed to read from DHT22!");
    return;
  }

  Serial.print("Humidity: ");
  Serial.print(h);
  Serial.print(" %  |  ");

  Serial.print("Temperature: ");
  Serial.print(t);
  Serial.print(" °C  |  ");
  Serial.print(f);
  Serial.println(" °F");

  delay(1000);  // DHT22 reads every 2 seconds
}

void displayLCD(){ 
  lcd.clear();  

  lcd.setCursor(0, 0); 
  lcd.print(t);
  lcd.print("C ");
  lcd.print(f); 

  lcd.setCursor(0, 1);
  lcd.print("Thickness:"); 
  lcd.print(thickVal);
   
}

void testDevice(){
servo.write(0); 
delay(3000);  
servo.write(180);
delay(3000);   

//buzzMe(3);  
//  inductiveVal  = analogRead(analogPin);
//  Serial.println(inductiveVal);

//if(thickness >= 10 && ) {
//  
//}

}