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

// Initialize the LCD, address 0x27 for a 16x2 LCD screen
LiquidCrystal_I2C lcd(0x27, 16, 2);
Servo myservo;  // create servo object to control a servo

// Constants for ultrasonic sensor
const int trigPin = 9;   // Trigger pin for ultrasonic sensor
const int echoPin = 10;  // Echo pin for ultrasonic sensor
const int servoPin = 6;  // Servo motor pin
const int threshold = 50; // Threshold distance in cm

// Variables for ultrasonic sensor
long duration;
int distance;

// Variables for lenght of scrolltext
int lcdWidth = 16; // Width of the LCD (number of characters)
// Servo motor position variable
int val;

// LCD scrolling variables
String Doorlock = "Door is Closed";
String Dooropen = "Door is Opened";
String initMessage = "Ebakoh Ugbalo Project";
String scrollMessage;
int scrollIndex = 0;
int scrollDelay = 250;  // Delay for scroll speed

void setup() {
  // Start serial communication
  Serial.begin(9600);

  // Set pin modes for ultrasonic sensor
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);

  // Attach servo to pin
  myservo.attach(servoPin);

  // Initialize the LCD
  lcd.begin(16, 2);  // 16 columns, 2 rows
  scrollText(initMessage, 0);
  delay(1000);
  lcd.clear();       // Clear the display
  lcd.print("Device Ready");
  delay(1000);
  lcd.clear(); 
  Serial.println("System initialized. Waiting for an object...");
  delay(2000); // Wait 2 seconds before starting measurements
  // Seed the random generator with an arbitrary analog input
  randomSeed(analogRead(1));
}

void loop() {
  // Automatically trigger ultrasonic sensor at random angles every 1000ms
  for (int i = 0; i < 180; i++) {
    distance = random(0, 101);
    // Generate a random servo angle between 0 and 180
    int randomAngle = random(0, 181);
    myservo.write(randomAngle);  // Set the servo to the random position

    // Send ultrasonic pulse
    digitalWrite(trigPin, LOW);
    delayMicroseconds(2);
    digitalWrite(trigPin, HIGH);
    delayMicroseconds(10);
    digitalWrite(trigPin, LOW);

    // Measure the time it takes for the echo to be received
    duration = pulseIn(echoPin, HIGH);

    // Calculate the distance based on the speed of sound
    //distance = duration * 0.034 / 2;  // Divide by 2 for round-trip time

    // Print the distance to the Serial Monitor
    Serial.print("Distance: ");
    Serial.print(distance);
    Serial.println(" cm");
    // Update LCD display
    displayOnLCD(distance, val);
    // Check if the distance is below the threshold
    if (distance < threshold) {
      // Map the distance to a servo angle between 0 and 180
      val = map(distance, 0, threshold, 0, 180);
      myservo.write(val);  // Set the servo position
      Serial.print("Servo angle: ");
      Serial.println(val);
      //lcd.setCursor(0, 1);  // Set the cursor to the beginning of the second row
      scrollText(Dooropen, 1);  // Print "Door Open" with extra spaces to clear row
    } else {
      // If no object is close enough, reset the servo to 0 position
      myservo.write(0);
      Serial.println("No object detected, servo reset to 0.");
      // Clear the second row if no object is detected
      //lcd.setCursor(0, 1);  // Set the cursor to the beginning of the second row
      scrollText(Doorlock, 1);   // Clear the second row by printing empty spaces
    }

    

    delay(500);  // Wait for 1000 milliseconds before the next reading
  }
}

// Function to display distance and servo angle on the LCD
void displayOnLCD(int distance, int servoAngle) {
  lcd.clear();  // Clear the display

  // Create the message to scroll
  scrollMessage = "Distance: " + String(distance) + " cm  Servo: " + String(servoAngle) + " degree";

  // Display the scrolling message
  scrollText(scrollMessage, 0);
}


 
  // Function to scroll text from right to left on the LCD
void scrollText(String message, int row) {
  // Add spaces to the message to clear the display
  String scrollMessage = "                " + message + "                ";
  for (int i = 0; i <= scrollMessage.length() - lcdWidth; i++) {
    lcd.setCursor(0, row);
    lcd.print(scrollMessage.substring(i, i + lcdWidth));
    delay(250); // Adjust delay to change the scrolling speed
  }
}