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

// Pin definitions for Ultrasonic Sensor and other components
#define TRIG_PIN 9   // Trig pin connected to D5 (Digital Pin 5)
#define ECHO_PIN 10  // Echo pin connected to D6 (Digital Pin 6)
#define RELAY_PIN 7  // Relay pin connected to D7 (Digital Pin 7)
#define LED_PIN 8    // LED pin connected to D8 (Digital Pin 8)
#define BUTTON_PIN 13

// Constants
const int tankHeight = 400;  // Height of water tank in cm
const float tankHeightP = 100.0;  // Maximum tank percentage
const float lowWaterLevel = 100;  // Water level threshold in cm
const float lowWaterLevelP = lowWaterLevel / tankHeight * 100.0;  // Low water level as a percentage
const float maxHeightP = 95; 

bool pumpOn = false;  // Flag to keep track of the pump status
bool LED = false;

// Set the LCD address (replace 0x27 with your I2C address)
LiquidCrystal_I2C lcd(0x27, 20, 4);  // 16x4 LCD with I2C module

// Function to measure distance from the sensor to the water surface
float measureDistance() {
    digitalWrite(TRIG_PIN, LOW);
    delayMicroseconds(2);
    digitalWrite(TRIG_PIN, HIGH);
    delayMicroseconds(10);
    digitalWrite(TRIG_PIN, LOW);
  
    long duration = pulseIn(ECHO_PIN, HIGH, 30000); // Timeout after 30ms

    long distance = duration * 0.034 / 2;  // Convert to cm

    // Calculate percentage of distance relative to tank height
    float distanceP = (float)distance / (float)tankHeight * 100.0;
    return distanceP;
}

void setup() {
    // Initialize serial monitor (optional for debugging)
    Serial.begin(9600);
  
    // Initialize sensor pins
    pinMode(TRIG_PIN, OUTPUT);
    pinMode(ECHO_PIN, INPUT);
  
    // Initialize relay and LED pins
    pinMode(RELAY_PIN, OUTPUT);
    digitalWrite(RELAY_PIN, LOW);  // Turn off the relay initially
    pinMode(LED_PIN, OUTPUT);
    digitalWrite(LED_PIN, LOW);  // Turn off the LED initially
    pinMode(BUTTON_PIN, INPUT);
    digitalWrite(BUTTON_PIN, LOW);

    // Initialize the LCD
    lcd.init();
    lcd.backlight();  // Turn on the backlight
    lcd.setCursor(0, 0);
    lcd.print("Water Level: ");
    lcd.setCursor(0, 2);
    lcd.print("Pumper's status: ");
}

void loop() {

  int button=digitalRead(BUTTON_PIN);// Read the button status


    // Measure the water level as a percentage
    float distanceP = measureDistance();
    if (distanceP < 0) { // Check for error in distance measurement
        lcd.setCursor(0, 1);
        lcd.print("Error in sensor  ");
        return; // Skip further processing
    }

    float waterLevel = tankHeightP - distanceP;  // Calculate water level percentage
    Serial.print(waterLevel);
    Serial.println(" %");

    // Display water level on the LCD
    lcd.setCursor(0, 1);  // Second row, first column
    lcd.print(waterLevel);
    lcd.print(" %   ");  // Clear extra characters

    // Check if water level is below the low threshold and the pump is off
    if (waterLevel < lowWaterLevelP && !pumpOn) {
        pumpOn = true;  // Turn on the pump
        digitalWrite(RELAY_PIN, HIGH);  // Activate the pump
        lcd.setCursor(0, 3);  // Fourth row, first column
        lcd.print("Pump: Active    ");  // Display Pump Active on the LCD


    }
    // Check if water level has reached the maximum level and the pump is on
    else if (waterLevel >= maxHeightP && pumpOn) {
        pumpOn = false;  // Turn off the pump
        digitalWrite(RELAY_PIN, LOW);  // Deactivate the pump
        lcd.setCursor(0, 3);
        lcd.print("Pump: Stopped    ");  // Display Pump Stopped on the LCD
        digitalWrite(LED_PIN, LOW); // Ensure LED is off
    }
    // Display pump inactive status if neither condition is met
    else if (!pumpOn) {
        lcd.setCursor(0, 3);
        lcd.print("Pump: Inactive   ");  // Display Pump Inactive on the LCD
        digitalWrite(RELAY_PIN, LOW);   // Ensure the pump remains off
    }

            // Store the initial water level when the pump is activated
        float initialWaterLevel = waterLevel;

        delay(3000);  // Wait for 3 seconds before checking water level again

        // Measure water level again after 3 seconds
        distanceP = measureDistance();
        waterLevel = tankHeightP - distanceP;

        // Check if the water level has increased after 5 seconds
        if (waterLevel <= initialWaterLevel && pumpOn) {
            LED = true;
            digitalWrite(RELAY_PIN, LOW);
            digitalWrite(LED_PIN, HIGH);  // Turn on LED to indicate issue
            Serial.println("Water level not increasing after 5 seconds!");
        } else {
            digitalWrite(LED_PIN, LOW);   // Turn off LED if water level is increasing
        }

        if(button==HIGH && LED){
          pumpOn = false;
          digitalWrite(LED_PIN, LOW);
          return;
        }


    delay(100);  // Delay for 2 seconds before the next measurement
}