#Ali Rashidi
from machine import Pin, PWM
from time import sleep_us, ticks_us, ticks_diff, sleep

#pin haye mored estefadeh
trig_pin = Pin(28, Pin.OUT)
echo_pin = Pin(27, Pin.IN)
led = PWM(Pin(26))

#tanzim ferq led
led.freq(1000)

def measure_distance():
   
    #ersal palse kotah baraye tahrik sensor
    trig_pin.off()
    sleep_us(2)  #zaman kami baraye khamosh kardan triger
    trig_pin.on()
    sleep_us(10) #ersal palse 10micro.s
    trig_pin.off()

    #andaze giriye zaman bazgasht palse echo
    while echo_pin.value() == 0:
        start_time = ticks_us()  #zaman shoroee palse echo
    while echo_pin.value() == 1:
        end_time = ticks_us()    #zaman payan palse echo

    #mohasebe modat zaman palse va tabdil be fasele
    duration = ticks_diff(end_time, start_time)
    distance_cm = (duration * 0.0343) / 2

    return distance_cm

def set_led_brightness(distance):
   
    max_distance = 100  #hadaksar fasele baraye roshanaee kamel
    min_distance = 2    #hadaghal fasele baraye khamosh kardan kamel

    #mahdod kardan fasele andazegiri shode be mahdode mojaz
    distance = max(min_distance, min(max_distance, distance))

    #mohasebe duty cycle be sorat maqoos
    duty = int(((max_distance - distance) / (max_distance - min_distance)) * 65535)
    led.duty_u16(duty)  #tanzim duty cycle led

    #mohasebe darsad roshanaee
    brightness_percent = (duty / 65535) * 100
    return brightness_percent

while True:
    distance = measure_distance()          #andaze giriye fasele
    brightness = set_led_brightness(distance)  #tanzim shedat noor led bar asas fasele
    print(f"Distance: {distance:.2f} cm, LED Brightness: {brightness:.2f}%")  #namayesh fasele va darsad roshanaee
    sleep(0.1)