#include <SPI.h>

byte symbol[8] = {0x60, 0xF0, 0xF0, 0x7F, 0x07, 0x06, 0x0C, 0x08};

const byte NOOP = 0x0;
const byte DECODEMODE = 0x9;
const byte INTENSITY = 0xA;
const byte SCANLIMIT = 0xB;
const byte SHUTDOWN = 0xC;
const byte DISPLAYTEST = 0xF;

void setup() {
    pinMode(10, OUTPUT);
    digitalWrite(10, HIGH); // Set chip select high
    SPI.begin();

    // Initialize the MAX7219
    max7219(SCANLIMIT, 7);    // 8 digits
    max7219(DECODEMODE, 0);   // No decode for digits
    max7219(INTENSITY, 8);    // Set intensity (0-15)
    max7219(DISPLAYTEST, 0);   // Disable display test
    max7219(SHUTDOWN, 1);      // Wake up the MAX7219

    // Clear the display
    for (byte i = 0; i < 8; i++) {
        max7219(i + 1, 0);
    }
}

void loop() {
    // Display each byte from the symbol array
    for (byte i = 0; i < 8; i++) {
        max7219(i + 1, symbol[i]);
    }
    delay(1000);  // Delay to make the changes visible
}

void max7219(byte reg, byte data) {
    digitalWrite(10, LOW);      // Start communication
    SPI.transfer(reg);              // Send register address
    SPI.transfer(data);             // Send data
    digitalWrite(10, HIGH);         // End communication
}