// Define pins
const int potPin = A0;        // Potentiometer input
const int ledPin = 9;         // LED brightness control (PWM)
const int barGraphPins[] = {22, 23, 24, 25, 26, 27, 28, 29, 30, 31}; // Bar graph segments

// Variables
int potValue = 0;             // Potentiometer reading (0-1023)
unsigned long previousMillis = 0; // For LED blinking
bool ledState = LOW;          // Current state of LED when blinking
const long blinkInterval = 2000; // Interval for blinking (2 seconds)

void setup() {
  // Initialize LED pin as output
  pinMode(ledPin, OUTPUT);
  
  // Initialize all bar graph pins as outputs
  for (int i = 0; i < 10; i++) {
    pinMode(barGraphPins[i], OUTPUT);
    digitalWrite(barGraphPins[i], LOW); // Ensure all segments are off at start
  }
  
  // LED starts off
  analogWrite(ledPin, 0);
}

void loop() {
  // Read potentiometer value
  potValue = analogRead(potPin);
  
  // Control bar graph segments based on potentiometer value
  updateBarGraph(potValue);
  
  // Control LED brightness or blinking
  if (potValue == 1023) {
    // Blink the LED at 0.25 Hz when potentiometer is at max
    unsigned long currentMillis = millis();
    
    if (currentMillis - previousMillis >= blinkInterval) {
      previousMillis = currentMillis;
      ledState = !ledState;
      digitalWrite(ledPin, ledState ? HIGH : LOW);
    }
  } else {
    // Set LED brightness proportional to potentiometer value
    analogWrite(ledPin, map(potValue, 0, 1023, 0, 255));
  }
}

// Update bar graph based on potentiometer value
void updateBarGraph(int value) {
  // Determine number of segments to light based on specific ranges
  int segmentsToLight = 0;
  
  if (value <= 102) {
    segmentsToLight = 0;
  } else if (value <= 204) {
    segmentsToLight = 1;
  } else if (value <= 306) {
    segmentsToLight = 2;
  } else if (value <= 408) {
    segmentsToLight = 3;
  } else if (value <= 510) {
    segmentsToLight = 4;
  } else if (value <= 612) {
    segmentsToLight = 5;
  } else if (value <= 714) {
    segmentsToLight = 6;
  } else if (value <= 816) {
    segmentsToLight = 7;
  } else if (value <= 918) {
    segmentsToLight = 8;
  } else if (value <= 920) {
    segmentsToLight = 9;
  } else {
    segmentsToLight = 10;
  }
  
  // Turn on/off segments accordingly
  for (int i = 0; i < 10; i++) {
    if (i < segmentsToLight) {
      digitalWrite(barGraphPins[i], HIGH); // Turn on segment
    } else {
      digitalWrite(barGraphPins[i], LOW);  // Turn off segment
    }
  }
}