Basic Scoreboard

.ino

#include <RGBmatrixPanel.h>

#define CLK  8   // USE THIS ON ARDUINO UNO, ADAFRUIT METRO M0, etc.
#define OE   9
#define LAT 10
#define A   A0
#define B   A1
#define C   A2

RGBmatrixPanel matrix(A, B, C, CLK, LAT, OE, false);

// Score variables
int leftScore = 0;
int rightScore = 0;

void setup() {
  Serial.begin(9600);
  matrix.begin();
  
  // Display "A" in red on the left, on top of leftScore
  matrix.setCursor(2, 2);
  matrix.setTextSize(1);
  matrix.setTextColor(matrix.Color333(7, 0, 0));
  matrix.print("A");

  // Display "B" in blue on the right, on top of rightScore
  matrix.setCursor(18, 2);
  matrix.setTextColor(matrix.Color333(0, 0, 7));
  matrix.print("B");

  matrix.swapBuffers(false); // Display the initial frame
}

void loop() {
  if (Serial.available() > 0) {
    char command = Serial.read();
    
    switch (command) {
      case 'X':
        // Up count for left score
        leftScore++;
        break;
      case 'Y':
        // Down count for left score
        leftScore--;
        break;
      case 'E':
        // Up count for right score
        rightScore++;
        break;
      case 'F':
        // Down count for right score
        rightScore--;
        break;
    }

    // Update display
    updateDisplay();
  }
}

void updateDisplay() {
  // Clear the display
  matrix.fillScreen(matrix.Color333(0, 0, 0));

  // Draw "A" in red on the left, on top of leftScore
  matrix.setCursor(2, 0);
  matrix.setTextSize(1);
  matrix.setTextColor(matrix.Color333(7, 0, 0));
  matrix.print("A");
  matrix.setCursor(2, 10);
  matrix.print(leftScore);

  // Draw '-' between leftScore and rightScore
  matrix.setCursor(12, 10);
  matrix.setTextColor(matrix.Color333(7, 7, 7));
  matrix.print("-");

  // Draw "B" in blue on the right, on top of rightScore
  matrix.setCursor(18, 0);
  matrix.setTextColor(matrix.Color333(0, 0, 7));
  matrix.print("B");
  matrix.setCursor(18, 10);
  matrix.print(rightScore);

  matrix.swapBuffers(false); // Display the updated frame
}