// Define the pins connected to the 74HC595 ICs
#define DATA_PIN 2    // Connect to DS (serial data input) pin of 74HC595
#define CLOCK_PIN 3   // Connect to SHCP (shift register clock input) pin of 74HC595
#define LATCH_PIN 4   // Connect to STCP (storage register clock input) pin of 74HC595

void setup() {
  // Set the 74HC595 control pins as outputs
  pinMode(DATA_PIN, OUTPUT);
  pinMode(CLOCK_PIN, OUTPUT);
  pinMode(LATCH_PIN, OUTPUT);
}

void loop() {
  // Define the LED matrix pattern (8x8 matrix)
  byte matrixPattern[] = {
    B10000000,
    B01000000,
    B00100000,
    B00010000,
    B00001000,
    B00000100,
    B00000010,
    B00000001
  };

  // Loop through the LED matrix pattern
  for (int i = 0; i < 8; i++) {
    updateShiftRegisters(matrixPattern[i]);
    delay(500);  // Delay for demonstration purposes
  }
}

// Function to update the shift registers with the desired LED matrix pattern
void updateShiftRegisters(byte rowData) {
  // Loop through both shift registers
  for (int shiftRegisterIndex = 0; shiftRegisterIndex < 2; shiftRegisterIndex++) {
    // Calculate the data to be sent to the shift register
    byte dataToSend = (rowData << shiftRegisterIndex);

    // Send the data to the shift register
    shiftOut(DATA_PIN, CLOCK_PIN, MSBFIRST, dataToSend);
  }

  // Latch the data into the storage register for both shift registers
  digitalWrite(LATCH_PIN, HIGH);
  digitalWrite(LATCH_PIN, LOW);
}