from machine import Pin, SoftI2C
from i2c_lcd import I2cLcd
import utime

trigger=Pin(27,Pin.OUT) 
echo=Pin(26,Pin.IN)

adress = 0x27
i2c = SoftI2C(scl=Pin(22), sda=Pin(21), freq=100000) # connect scl to GPIO 22, sda to GPIO 21
lcd = I2cLcd(i2c, adress, 2, 16)

def ultra():
    trigger.off()
    utime.sleep_us (2)
    trigger.on() 
    utime.sleep_us (5)
    trigger.off()
    while echo.value() == 0:
        signal_off = utime.ticks_us()
    while echo.value() == 1:
        signal_on = utime.ticks_us()
    try:
        time_passed = signal_on - signal_off
    except NameError:
        return 0
    return time_passed/58

while True:
    distance = ultra()
    lcd.putstr(f'{distance}')
    utime.sleep(4)
    lcd.clear()