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

// Initialize I2C LCD (Address 0x27 is common)
LiquidCrystal_I2C lcd(0x27, 16, 2); // I2C Address 0x27 for 16x2 LCD

// Pin definitions
int POT1  = A3;
int POT2  = A2;
int BUTTON1 = 2;
int LED = 4;
int BUTTON2  = 3;
int BUZZER  = 5;

volatile bool ledTriggered = false;
volatile bool buzzerTriggered = false;
unsigned long ledStartTime = 0;
unsigned long buzzerStartTime = 0;
bool displayUpdated = false; // Flag for preventing repeated LCD updates

void ISR_Button1() {
    ledTriggered = true;
    ledStartTime = millis();
    displayUpdated = false; // Allow LCD update
}

void ISR_Button2() {
    buzzerTriggered = true;
    buzzerStartTime = millis();
    displayUpdated = false; // Allow LCD update
}

void setup() {
    // Initialize I2C LCD
    lcd.init();
    lcd.backlight(); // Turn on backlight

    // Set pin modes
    pinMode(POT1, INPUT);
    pinMode(POT2, INPUT);
    pinMode(LED, OUTPUT);
    pinMode(BUZZER, OUTPUT);
    pinMode(BUTTON1, INPUT_PULLUP);
    pinMode(BUTTON2, INPUT_PULLUP);

    // Ensure outputs are OFF initially
    digitalWrite(LED, LOW);
    digitalWrite(BUZZER, LOW);

    // Attach interrupts
    attachInterrupt(digitalPinToInterrupt(BUTTON1), ISR_Button1, FALLING);
    attachInterrupt(digitalPinToInterrupt(BUTTON2), ISR_Button2, FALLING);
}

void loop() {
    // Read potentiometer values
    int pot1_value = analogRead(POT1);
    int pot2_value = analogRead(POT2);

    // Convert to voltage
    float pot1_voltage = (pot1_value / 1023.0) * 2.5;
    float pot2_voltage = (pot2_value / 1023.0) * 5.0;

    // Handle LED (8 seconds) logic
    if (ledTriggered) {
        digitalWrite(LED, HIGH);
        if (!displayUpdated) {
            lcd.clear();
            lcd.setCursor(0, 0);
            lcd.print("LED ISR1 ON");
            lcd.setCursor(0, 1);
            lcd.print("8 seconds");
            displayUpdated = true; // Prevent multiple updates
        }
        if (millis() - ledStartTime >= 8000) { // After 8 seconds
            digitalWrite(LED, LOW);
            ledTriggered = false;
            lcd.clear(); // Clear LCD after LED off
        }
    }

    // Handle buzzer (6 seconds) logic
    if (buzzerTriggered) {
        digitalWrite(BUZZER, HIGH);
        if (!displayUpdated) {
            lcd.clear();
            lcd.setCursor(0, 0);
            lcd.print("BZR ISR2 ON");
            lcd.setCursor(0, 1);
            lcd.print("6 seconds");
            displayUpdated = true; // Prevent multiple updates
        }
        if (millis() - buzzerStartTime >= 6000) { // After 6 seconds
            digitalWrite(BUZZER, LOW);
            buzzerTriggered = false;
            lcd.clear(); // Clear LCD after buzzer off
        }
    }

    // If no LED or buzzer is active, display potentiometer values
    if (!ledTriggered && !buzzerTriggered) {
        lcd.setCursor(0, 0);
        lcd.print("POT1: ");
        lcd.print(pot1_voltage, 1);
        lcd.print("V ");
        lcd.print(pot1_value);

        lcd.setCursor(0, 1);
        lcd.print("POT2: ");
        lcd.print(pot2_voltage, 1);
        lcd.print("V ");
        lcd.print(pot2_value);
    }

    delay(500);  // Refresh the display every 500ms
}