from machine import Pin
import time


TRIGGER_PIN = 7
ECHO_PIN = 6

trigger = Pin(TRIGGER_PIN, Pin.OUT)
echo = Pin(ECHO_PIN, Pin.IN)

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

def wait(value, timeout):
    count = timeout
    while echo.value() != value and count > 0:
        count -= 1

def get_distance():
    send_trigger_pulse()
    wait(1, 10000) 
    start = time.ticks_us()
    wait(0, 10000) 
    end = time.ticks_us()
    duration = time.ticks_diff(end, start)
    distance = duration * 0.0343 / 2 
    return distance


while True:
    distance = get_distance()
    print("Distance: {:.2f} cm".format(distance))
    time.sleep(1)