// Upper Tank Sensor
#define TRIG_UPPER  26  
#define ECHO_UPPER  25  

// Lower Tank Sensor
#define TRIG_LOWER  14  
#define ECHO_LOWER  16  

// Upper Tank LED Indicators
#define UPPER_LOWLED   18  
#define UPPER_MIDLED   19  
#define UPPER_HIGHLED  21  

// Lower Tank LED Indicators
#define LOWER_LOWLED   5  
#define LOWER_HIGHLED  4  

// Motor Control
#define MOTOR  27  
#define MOTOR_LED  2   // Motor Indicator LED

void setup() {
    Serial.begin(115200);

    // Pin Modes for Upper Tank LEDs
    pinMode(UPPER_LOWLED, OUTPUT);
    pinMode(UPPER_MIDLED, OUTPUT);
    pinMode(UPPER_HIGHLED, OUTPUT);

    // Pin Modes for Lower Tank LEDs
    pinMode(LOWER_LOWLED, OUTPUT);
    pinMode(LOWER_HIGHLED, OUTPUT);

    // Pin Modes for Motor & Motor Indicator LED
    pinMode(MOTOR, OUTPUT);
    pinMode(MOTOR_LED, OUTPUT);
    digitalWrite(MOTOR, LOW); // Motor OFF initially
    digitalWrite(MOTOR_LED, LOW); // Motor LED OFF initially

    // Pin Modes for Ultrasonic Sensors
    pinMode(TRIG_UPPER, OUTPUT);
    pinMode(ECHO_UPPER, INPUT);
    pinMode(TRIG_LOWER, OUTPUT);
    pinMode(ECHO_LOWER, INPUT);
}

// Function to Measure Distance
int getDistance(int trigPin, int echoPin) {
    digitalWrite(trigPin, LOW);
    delayMicroseconds(2);
    digitalWrite(trigPin, HIGH);
    delayMicroseconds(10);
    digitalWrite(trigPin, LOW);

    int duration = pulseIn(echoPin, HIGH);
    int distance = duration / 58; // Convert to cm
    return distance;
}

void loop() {
    int upperLevel = getDistance(TRIG_UPPER, ECHO_UPPER);
    int lowerLevel = getDistance(TRIG_LOWER, ECHO_LOWER);

    Serial.print("Upper Tank Level: ");
    Serial.print(upperLevel);
    Serial.print(" cm, Lower Tank Level: ");
    Serial.println(lowerLevel);

    // Upper Tank LED Control
    if (upperLevel < 100) {
        digitalWrite(UPPER_LOWLED, LOW);
        digitalWrite(UPPER_MIDLED, HIGH);
        digitalWrite(UPPER_HIGHLED, HIGH);
    } 
    else if (upperLevel > 200 && upperLevel < 400) {
        digitalWrite(UPPER_LOWLED, HIGH);
        digitalWrite(UPPER_MIDLED, LOW);
        digitalWrite(UPPER_HIGHLED, HIGH);
    } 
    else if (upperLevel >= 400) {
        digitalWrite(UPPER_LOWLED, HIGH);
        digitalWrite(UPPER_MIDLED, HIGH);
        digitalWrite(UPPER_HIGHLED, LOW);
    }

    // Lower Tank LED Control
    if (lowerLevel < 100) {
        digitalWrite(LOWER_LOWLED, LOW);
        digitalWrite(LOWER_HIGHLED, HIGH);
    }  
    else if (lowerLevel >= 300) {
        digitalWrite(LOWER_LOWLED, HIGH);
        digitalWrite(LOWER_HIGHLED, LOW);
    }

    // Motor Control Logic & Motor Indicator LED
    if (upperLevel < 100 && lowerLevel > 100) { 
        digitalWrite(MOTOR, HIGH); // Turn ON motor
        digitalWrite(MOTOR_LED, HIGH); // Turn ON motor indicator
        Serial.println("Motor ON");
    } 
    else if (upperLevel >= 400 || lowerLevel < 100) { 
        digitalWrite(MOTOR, LOW); // Turn OFF motor
        digitalWrite(MOTOR_LED, LOW); // Turn OFF motor indicator
        Serial.println("Motor OFF");
    }

    delay(2000); // Wait 2 seconds before next measurement
}