from machine import Pin
import utime, math

PIR_PIN = 15
LED_PIN = 16
SAMPLES_TARGET = 50

led = Pin(LED_PIN, Pin.OUT, value=0)
pir = Pin(PIR_PIN, Pin.IN)

t_rise = 0
flag = False

n = 0
sumv = 0.0
sumsq = 0.0
minv = None
maxv = None

def on_rise(pin):
    global t_rise, flag
    t_rise = utime.ticks_us()
    flag = True

pir.irq(handler=on_rise, trigger=Pin.IRQ_RISING)

while True:
    if flag:
        flag = False
        led.value(1)
        t2 = utime.ticks_us()
        d = utime.ticks_diff(t2, t_rise)
        print("RESP_US=", d)
        if minv is None or d < minv: minv = d
        if maxv is None or d > maxv: maxv = d
        sumv += d
        sumsq += d * d
        n += 1
        if n >= SAMPLES_TARGET:
            mean = sumv / n
            std = math.sqrt((sumsq - (sumv * sumv) / n) / (n - 1)) if n > 1 else 0.0
            print("PLATFORM,GPIO_IN,GPIO_OUT,SAMPLES,MEAN_US,STD_US,MIN_US,MAX_US")
            print("Raspberry_Pi_Pico,GP15,GP16,{},{:.0f},{:.0f},{},{}".format(n, mean, std, minv, maxv))
            break
    if pir.value() == 0:
        led.value(0)
    utime.sleep_ms(2)