#include <LiquidCrystal.h>  // initialize the library "Liquid crystal"

const int echoPin = 6;// attach D2 of the Arduino to pin Echo of the sonar sensor
const int trigPin = 7;//attach D3 of the Arduino to pin Trig of the sonar sensor
const int buttonPin = 20;// button pin onboard of the microcontroller

int LEDstate = 0;
// declare the Pins needed for the LCD screen
const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;

LiquidCrystal lcd(rs, en, d4, d5, d6, d7);

void setup() { 
  pinMode(tPin, OUTPUT); // Sets the trigPin as an OUTPUT
  pinMode(ePin, INPUT); // Sets the echoPin as an INPUT
  pinMode(buttonPin, INPUT); //set button as input
  pinMode(LED_BUILTIN, OUTPUT); // set LED as output
  Serial.begin(9600); // // Serial Communication is set at 9600  baud
  Serial.print("Welome\n");
  Serial.print("Thomas Pinckers\n");
  Serial.print("2107027\n");
  Serial.print("Sensors and Actuators\n");  
  lcd.begin(16, 2);  
  digitalWrite(LED_BUILTIN, HIGH);
}
void loop() {
  // Clears the trigPin condition
  int centimeter = distance();
  if(centimeter >= 10 || centimeter <= 180){ // looks if the distance is between 180 adn 10
    Display(99, centimeter);  
  }
  if(centimeter < 10){ // looks if the distance is les than 10
    Display(1, centimeter);
  }
  if(distance() > 180){ // looks if the distance is more than 180
    Display(2, centimeter);
  }
  MakeLED(); // checks if the button is pressed 
}
int distance() {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2); // Sets the trigPin HIGH (LOW) for 2 microseconds
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);  // Sets the trigPin HIGH (ACTIVE) for 10 microseconds
  digitalWrite(trigPin, LOW); // Reads the echoPin, returns the sound wave travel time in microseconds
  long duration = pulseIn(echoPin, HIGH);
  // Calculating the distance
  int centimeter = duration * 0.034 / 2; // Speed of sound wave divided by 2 (go and back)
  return(centimeter);
}
void Display(int state, int centimeter) { // state if the screan
  lcd.clear();
  switch(state){
    case 1:
      lcd.setCursor(1, 1);
      lcd.print("Distance: < 10");
      break;
    case 2:
      lcd.setCursor(1, 1);
      lcd.print("Distance: > 180");
      LEDstate = 1;
      break;
    default:
      lcd.setCursor(1, 1);
      lcd.print("Distance: ");
      lcd.print(centimeter);
      break;
  }
  lcd.setCursor(0, 0);
  lcd.print("Student : Jaimy");
}
void MakeLED() {
  int LEDbutton = digitalRead(button1);
  int lastState;
  if(LEDbutton != lastState){
    if(LEDbutton == HIGH){
      LEDstate = 0;
    }
  }
  digitalWrite(LED_BUILTIN, LEDstate); // make the LED output the same as the state
  lastState = LEDbutton;
}