# from machine import Pin, PWM
# import time

# TRIG_PIN = 26
# ECHO_PIN = 25

# LED_PIN = 18

# trigger = Pin(TRIG_PIN, Pin.OUT)
# echo = Pin(ECHO_PIN, Pin.IN)

# led = PWM(Pin(LED_PIN))

# def get_distance():
#     trigger.value(1)
#     time.sleep_us(10)
#     trigger.value(0)

#     while echo.value() == 0:
#         pass
#     start = time.ticks_us()

#     while echo.value() == 1:
#         pass
#     end = time.ticks_us()

#     distance = ((end - start) / 2) / 29.1
#     return distance

# while True:
#     distance = get_distance()
#     print('Distance:', distance, 'cm')

#     if distance < 50:
#         led.duty(1023) 
#     elif distance < 100:
#         led.duty(int(1023 * 0.8))
#     elif distance < 180:
#         led.duty(int(1023 * 0.5)) 
#     elif distance < 200:
#         led.duty(int(1023 * 0.2))
#     else:
#         led.duty(0)

#     time.sleep(0.1)




from machine import Pin, PWM
import time

TRIG_PIN = 26
ECHO_PIN = 25
LED_PIN = 18

trigger = Pin(TRIG_PIN, Pin.OUT)
echo = Pin(ECHO_PIN, Pin.IN)
led = PWM(Pin(LED_PIN))

def get_distance():
    trigger.value(1)
    time.sleep_us(10)
    trigger.value(0)

    while echo.value() == 0:
        pass
    start = time.ticks_us()

    while echo.value() == 1:
        pass
    end = time.ticks_us()

    distance = ((end - start) / 2) / 29.1
    return distance

while True:
    distance = get_distance()
    print('Distance:', distance, 'cm')

    brightness = int((200 - min(distance, 200)) / 200 * 1023)
    led.duty(brightness)