arduino.ino

const int button[8] = {0, 1, 2, 3, 4, 5, 6, 7};
const int LED[16] = {8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23};

int buttonState[8];

void setup() {
  for (int i = 0; i < 8; i++) {
    pinMode(button[i], INPUT_PULLUP);
  }
  for (int i = 0; i < 16; i++) {
    pinMode(LED[i], OUTPUT);
  }
  Serial.begin(9600);
}

void loop() {
  for (int i = 0; i < 8; i++) {
    buttonState[i] = digitalRead(button[i]);
    if (buttonState[i] == LOW) {
      digitalWrite(LED[2 * i], !digitalRead(LED[2 * i]));
      digitalWrite(LED[2 * i + 1], !digitalRead(LED[2 * i + 1]));
      if (digitalRead(LED[2 * i]) == HIGH) {
        Serial.println("M" + String(i) + "0");
      }
      else {
        Serial.println("M" + String(i) + "1");
      }
    }
  }
}