from machine import Pin, PWM
from time import sleep, sleep_us, ticks_us, ticks_diff

#tarif pin haye ersal va daryaft amvaj seda ultrasonic va tarif pin buzzer
trig_pin = Pin(28, Pin.OUT)
echo_pin = Pin(27, Pin.IN)
buzzer_pin = PWM(Pin(26,Pin.OUT))  #tarif pin besorat pwm

def measure_distance():
    # tashkil va ersal palse triger
    trig_pin.off()
    sleep_us(2)
    trig_pin.on()
    sleep_us(10)
    trig_pin.off()

    # entezar baraye shoroee palse echo
    while echo_pin.value() == 0:  #monazer shoroee palse echo mimanim
        start_time = ticks_us()   #zakhire zaman shoroee palse echo
        

    
    #enteza baraye payan palse echo
    while echo_pin.value() == 1:  #montazer payane palse echo mimanim
        end_time = ticks_us()     #zakhire zaman payan palse echo
        
        

    
    #mohasebe modat zaman palse echo
    duration = ticks_diff(end_time, start_time)

    
    #tabdil modat zaman palse be fasele bar hasbe cm
    distance_cm = (duration * 0.0343) / 2

    return distance_cm

def detect_and_alert():
    distance = measure_distance()  #andaze giriee fasele ba sensor

    if distance is None:  
        print("Error measuring distance!")  #dar sorat khata dar andaze giri, payam khata, namayesh dade mishavad
        return

    print(f"Distance: {distance:.2f} cm")  #namayesh fasele andaze giri shode

    
    #baresi inke aya fasele dar mahdode moshakhas shode ghara darad ya kheyr
    if 20 <= distance <= 40:
        print("!!!DETECTION Person!!!")
        buzzer_pin.freq(3000)         #tanzim ferecans buzzer bar roye 3000hz
        buzzer_pin.duty_u16(32768)    #tanzim duty cycle buzzer bar roye 50% az 65536 be 32768
        sleep(0.8)                    #roshan mandan buzzer baraye 0.8s
        buzzer_pin.duty_u16(0)        #khamosh kardan buzzer


while True:
    detect_and_alert()  #ejraye halghe asli baraye andaze giri va hoshdar
    sleep(1)