// Pin definition
const int digitalPin = D1;  // Sensor D0 -> XIAO D1 (P27)

int lastState = 1; // Initial state (no detection)

void setup() {
  Serial.begin(115200);
  pinMode(digitalPin, INPUT);

  Serial.println("IR Goal Detection System");
}

void loop() {
  int currentState = digitalRead(digitalPin);

  // Detect transition (object passing)
  if (lastState == 1 && currentState == 0) {
    Serial.println("GOAL!! ⚽");
  } else {
    // No detection
    Serial.println("0");
  }

  // Update previous state
  lastState = currentState;

  delay(50);
}