Logic gates Tester

const int A_PIN = 13;  // вход A към чипа
const int B_PIN = 12;  // вход B към чипа
const int C_PIN = 11;  // вход A към чипа
const int D_PIN = 10;  // вход B към чипа
const int Y_PIN = 9;  // изход от чипа към Arduino
const int LED_OK = 2;
const int LED_NOK = 3;

struct Vec {
  uint8_t a;
  uint8_t b;
  uint8_t c;
  uint8_t d;
  uint8_t expected;
};

Vec tests[] = {
  {0, 0, 0, 0, 0},
  {0, 0, 0, 1, 0},
  {0, 0, 1, 0, 0},
  {0, 0, 1, 1, 0},
  {0, 1, 0, 0, 0},
  {0, 1, 0, 1, 0},
  {0, 1, 1, 0, 0},
  {0, 1, 1, 1, 0},
  {1, 0, 0, 0, 0},
  {1, 0, 0, 1, 0},
  {1, 0, 1, 0, 0},
  {1, 0, 1, 1, 0},
  {1, 1, 0, 0, 0},
  {1, 1, 0, 1, 1},
  {1, 1, 1, 0, 1},
  {1, 1, 1, 1, 1},
};

void setup() {
  Serial.begin(115200);

  pinMode(A_PIN, OUTPUT);
  pinMode(B_PIN, OUTPUT);
  pinMode(C_PIN, OUTPUT);
  pinMode(D_PIN, OUTPUT);
  pinMode(Y_PIN, INPUT);
  pinMode(LED_OK, OUTPUT);
  pinMode(LED_NOK, OUTPUT);
  Serial.println("74HC AND tester start");
  bool pass = true;

  for (int i = 0; i < 16; i++) {
    digitalWrite(A_PIN, tests[i].a);
    digitalWrite(B_PIN, tests[i].b);
    digitalWrite(C_PIN, tests[i].c);
    digitalWrite(D_PIN, tests[i].d);
    delayMicroseconds(10); // време за установяване

    int y = digitalRead(Y_PIN);

    if (y != tests[i].expected) {
      pass = false;
      Serial.print("FAIL: A=");
      Serial.print(tests[i].a);
      Serial.print(" B=");
      Serial.print(tests[i].b);
      Serial.print(" C=");
      Serial.print(tests[i].c);
      Serial.print(" D=");
      Serial.print(tests[i].d);
      Serial.print(" -> Y=");
      Serial.print(y);
      Serial.print(" expected ");
      Serial.println(tests[i].expected);
    }
  }

  if (pass){
    Serial.println("PASS: gate OK");
    digitalWrite(LED_OK, HIGH);
  } else {
    Serial.println("Fail: NOK");
    digitalWrite(LED_NOK, HIGH);
  }
}

void loop() {
}