#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

// Define screen dimensions and OLED reset pin
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET -1
#define OLED_SDA 21
#define OLED_SCL 22

// Define PIR sensor and LED pins
#define PIR_PIN 3
#define LED_PIN 2

// Create an instance of the OLED display
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

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

  // Initialize the OLED display with the correct I2C address
  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { 
    Serial.println(F("SSD1306 allocation failed"));
    for (;;); // Infinite loop to halt the program if display initialization fails
  }

  // Clear the display and set initial text properties
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0, 0);

  // Set up PIR sensor and LED pin modes
  pinMode(PIR_PIN, INPUT);
  pinMode(LED_PIN, OUTPUT);

  // Print initial message to the display
  display.println("Setup complete!");
  display.display();
  delay(2000); // Pause for 2 seconds
}

void loop() {
  int motionDetected = digitalRead(PIR_PIN); // Read PIR sensor value

  // Clear the display for the new message
  display.clearDisplay();
  display.setCursor(0, 0);

  if (motionDetected == HIGH) {
    display.println("Motion detected!");
    digitalWrite(LED_PIN, HIGH); // Turn on LED
  } else {
    display.println("No motion detected.");
    digitalWrite(LED_PIN, LOW); // Turn off LED
  }

  // Display the updated message
  display.display();
  
  // Delay for a second before the next reading
  delay(1000);
}