#define LED_PIN 5
#define SENSOR_PIN 4
#define THRESHOLD_DROP 1.05  // Trigger if signal drops 5% of baseline
#define MIN_DURATION 10     // Microseconds
#define MAX_DURATION 1000000 // 1 second

unsigned long lastBaselineUpdate = 0;
const unsigned long baselineInterval = 1000; // ms

int baseline = 0;

void setup() {
	Serial.begin(9600);
	pinMode(LED_PIN, OUTPUT);
	digitalWrite(LED_PIN, HIGH); // LED always on

	baseline = readSensorBaseline();
	Serial.print("Initial baseline: ");
	Serial.println(baseline);
}

void loop() {
	// Update baseline every 1 second
	if (millis() - lastBaselineUpdate >= baselineInterval) {
	int newBaseline = readSensorBaseline();

	// Optional: Only update if no ball is detected
	if (newBaseline < baseline * 1.1) {
		baseline = newBaseline;
		//Serial.print("Updated baseline: ");
		//Serial.println(baseline);
	}

	lastBaselineUpdate = millis();
	}

	int sensorValue = analogRead(SENSOR_PIN);
	unsigned long startTime = 0;

	// Trigger if signal rises (since your signal is normally low)
	if (sensorValue > baseline * THRESHOLD_DROP) {
	startTime = micros();

	while (analogRead(SENSOR_PIN) > baseline * THRESHOLD_DROP) {
		if ((micros() - startTime) > MAX_DURATION) break;
	}

	unsigned long duration = micros() - startTime;

	if (duration >= MIN_DURATION && duration <= MAX_DURATION) {
		Serial.print("Ball detected! Duration: ");
		Serial.print(duration);
		Serial.println(" us");
	}
	}

	delayMicroseconds(100);
}

int readSensorBaseline() {
	const int samples = 10;
	long total = 0;
	for (int i = 0; i < samples; i++) {
	total += analogRead(SENSOR_PIN);
	delay(5); // Small delay between samples
	}
	return total / samples;
}