#define PIR_PIN 15
#define LED_PIN 16

uint8_t prev = LOW;
unsigned long trials = 0, minD = 0xFFFFFFFFUL, maxD = 0, sumD = 0;

void setup() {
  pinMode(PIR_PIN, INPUT);
  pinMode(LED_PIN, OUTPUT);
  digitalWrite(LED_PIN, LOW);
  Serial1.begin(115200);
  delay(50);
  Serial1.println("event,trial,detect_to_led_on_us,min_us,max_us,avg_us");
}

void loop() {
  uint8_t s = digitalRead(PIR_PIN);
  if (s && !prev) {
    unsigned long t1 = micros();
    digitalWrite(LED_PIN, HIGH);
    unsigned long t2 = micros();
    unsigned long d = t2 - t1;
    trials++;
    if (d < minD) minD = d;
    if (d > maxD) maxD = d;
    sumD += d;
    unsigned long avg = sumD / trials;
    Serial1.print("rise,");
    Serial1.print(trials);
    Serial1.print(",");
    Serial1.print(d);
    Serial1.print(",");
    Serial1.print(minD);
    Serial1.print(",");
    Serial1.print(maxD);
    Serial1.print(",");
    Serial1.println(avg);
  }
  if (!s && prev) {
    digitalWrite(LED_PIN, LOW);
    Serial1.println("fall");
  }
  prev = s;
}