// Define pin numbers
const int ledPin = 8;    // LED connected to GPIO 8
const int ledPin1 = 5;   // Additional LED connected to GPIO 5
const int ledPin2 = 6;   // LED connected to GPIO 6
const int ledPin3 = 7;   // LED connected to GPIO 7
const int relayPin = 1;  // Relay connected to GPIO 1
const int buttonPin = 9; // Button connected to GPIO 9
const int voltagePin = 2; // Voltage sensor connected to GPIO 2

// Variable to store button state
int buttonState = 0;

void setup() {
  // Initialize the LED pins as outputs
  pinMode(ledPin, OUTPUT);
  pinMode(ledPin1, OUTPUT);
  pinMode(ledPin2, OUTPUT);
  pinMode(ledPin3, OUTPUT);

  // Initialize the relay pin as an output
  pinMode(relayPin, OUTPUT);
  
  // Initialize the button pin as an input
  pinMode(buttonPin, INPUT); // Use internal pull-up resistor

  // Initialize the voltage sensor pin as an input
  pinMode(voltagePin, INPUT);

  // Start with the LEDs and relay off
  digitalWrite(ledPin, LOW);
  digitalWrite(ledPin1, LOW);
  digitalWrite(ledPin2, LOW);
  digitalWrite(ledPin3, LOW);
  digitalWrite(relayPin, LOW);
  
  // Start the serial communication to send the voltage readings to the PC
  Serial.begin(115200);
  delay(1000); // Wait for serial monitor to open
}

void loop() {
  // Read the state of the push button
  buttonState = digitalRead(buttonPin);

  // Read the voltage from the voltage sensor
  int analogValue = analogRead(voltagePin);
  
  // Convert the analog value to voltage
  float voltage = analogValue * (3.3 / 4095.0);

  // Print the voltage to the serial monitor
  Serial.print("Voltage: ");
  Serial.print(voltage);
  Serial.println(" V");

  // Calculate the battery percentage
  float batteryPercentage = (voltage / 3.3) * 100;

  // Check if the button is pressed
  if (buttonState == HIGH) 
  {
    // Flash the LED based on battery percentage
    if (batteryPercentage >= 40 && batteryPercentage <= 100) {
      digitalWrite(ledPin2, HIGH);  // LED on GPIO 6
      delay(500);
      digitalWrite(ledPin2, LOW);
      delay(500);
    } else if (batteryPercentage >= 20 && batteryPercentage < 40) {
      digitalWrite(ledPin1, HIGH);  // LED on GPIO 5
      delay(500);
      digitalWrite(ledPin1, LOW);
      delay(500);
    } else if (batteryPercentage >= 5 && batteryPercentage < 20) {
      digitalWrite(ledPin3, HIGH);  // LED on GPIO 7
      delay(500);
      digitalWrite(ledPin3, LOW);
      delay(500);
    } else {
      // Turn off all LEDs if battery percentage is not in specified range
      digitalWrite(ledPin1, LOW);
      digitalWrite(ledPin2, LOW);
      digitalWrite(ledPin3, LOW);
    }

    // Blink the LED connected to GPIO 8
    digitalWrite(ledPin, HIGH);   
    delay(500);                  
    digitalWrite(ledPin, LOW);    
    delay(500);                   

    // Turn on the relay
    digitalWrite(relayPin, HIGH);
  } 
  else
  {
    // Ensure all LEDs and relay are off when button is not pressed
    digitalWrite(ledPin, LOW);
    digitalWrite(ledPin1, LOW);
    digitalWrite(ledPin2, LOW);
    digitalWrite(ledPin3, LOW);
    digitalWrite(relayPin, LOW);
  }

  // Small delay to prevent flooding the serial monitor
  delay(1000);
}