from machine import Pin, I2C, time_pulse_us
from ssd1306 import SSD1306_I2C
import time

# initialize SSD1306 OLED display
i2c = I2C(-1, scl=Pin(22), sda=Pin(21))
oled = SSD1306_I2C(128, 64, i2c)

# initialize HC-SR04 sensor pins
trig_pin = Pin(4, Pin.OUT)
echo_pin = Pin(5, Pin.IN)

while True:
    # trigger the sensor
    trig_pin.value(0)
    time.sleep_us(2)
    trig_pin.value(1)
    time.sleep_us(10)
    trig_pin.value(0)

    # measure the duration of the echo pulse
    duration_us = time_pulse_us(echo_pin, 1)
    
    # calculate the distance based on the duration
    distance_cm = duration_us / 58.0
    
    # display the distance on the SSD1306 OLED display
    oled.fill(0)
    oled.text("Distance:", 0, 0)
    oled.text("{:.2f} cm".format(distance_cm), 0, 16)
    oled.show()
    
    time.sleep(1)