from machine import Pin, Timer, I2C
from hcsr04 import HCSR04
from ssd1306 import SSD1306_I2C
i2c = I2C(sda=Pin(21), scl=Pin(22))
oled = SSD1306_I2C(128, 32, i2c)

sensor = HCSR04(trigger_pin=2, echo_pin=15,echo_timeout_us=1000000)

def hcsr04_isr(event):
  distance = sensor.distance_cm()
  print(distance)
  print(round(distance,2))
  oled.text('Distance (cm)', 0, 0)
  oled.text(str(round(distance,2)), 5, 20) 
  oled.show()

blink_timer = Timer(1)
blink_timer.init(period=5000, mode=Timer.PERIODIC, callback=hcsr04_isr)