// Define pins for shift register
#define DATA_PIN 8
#define CLOCK_PIN 9
#define LATCH_PIN 10

// Define pins for potentiometer and switch
#define POTENTIOMETER_PIN A0
#define SWITCH_PIN 11

// Define the number of shift registers
#define NUM_SHIFT_REGISTERS 2

// Global variable to store the LED pattern
uint16_t ledPattern = 0;

// Function to write data to shift registers
void writeData(uint16_t data) {
  digitalWrite(LATCH_PIN, LOW);
  for (int i = NUM_SHIFT_REGISTERS * 8 - 1; i >= 0; i--) {
    digitalWrite(CLOCK_PIN, LOW);
    digitalWrite(DATA_PIN, (data >> i) & 0x01);
    digitalWrite(CLOCK_PIN, HIGH);
  }
  digitalWrite(LATCH_PIN, HIGH);
}

void setup() {
  pinMode(DATA_PIN, OUTPUT);
  pinMode(CLOCK_PIN, OUTPUT);
  pinMode(LATCH_PIN, OUTPUT);
  pinMode(POTENTIOMETER_PIN, INPUT);
  pinMode(SWITCH_PIN, INPUT_PULLUP); // Enable internal pull-up resistor for the switch pin
}

void loop() {
  // Check if the switch is pressed
  bool switchState = digitalRead(SWITCH_PIN);
  if (switchState == LOW) {
    // If switch is pressed, turn on the LED bar graph

    // Read the value from the potentiometer
    int potValue = analogRead(POTENTIOMETER_PIN);

    // Map the potentiometer value to the range of LED brightness (0-1023 to 0-1023)
    int brightness = map(potValue, 0, 1023, 0, 1023);

    // Calculate the number of LEDs to light up based on the brightness
    int numLEDs = map(brightness, 0, 1023, 0, 10);

    // Create a bit pattern to represent the LED states
    ledPattern = 0;
    for (int i = 0; i < numLEDs; i++) {
      ledPattern |= (1 << i);
    }
  } else {
    // If switch is not pressed, turn off the LED bar graph
    ledPattern = 0;
  }

  // Write the data to the shift registers
  writeData(ledPattern);
}