#Import library ultrasonic, Oled, pwm time

import HCSR04
import ssd1306
from machine import SoftI2C, Pin, PWM
from time import sleep

#Declare connection pin using OOP
#For ultrasonic sensor

ultrasonic_sensor=HCSR04.HCSR04(trigger_pin=14,echo_pin=26,echo_timeout_us=500*2*30) #500 is speed of sound.

#for oled

i2c_oleddisplay= SoftI2C(scl=Pin(21), sda=Pin(22))
oled_width=128
oled_height=64
oled=ssd1306.SSD1306_I2C(oled_width,oled_height,i2c_oleddisplay)

#For Buzzer

buzzer=PWM(Pin(23),Pin.OUT)    

#for LED
led1 = Pin(19,Pin.OUT)
led2 = Pin(18,Pin.OUT)
led3 = Pin(5,Pin.OUT)

#Process

while True:
  distance_in_cm=ultrasonic_sensor.distance_cm()

  print('An object is detected in:', distance_in_cm,'cm')

  oled.fill(1) #1 means line number 1
  oled.text('Object detected',2,10,0)
  oled.text(str(distance_in_cm),5,20,0)
  oled.text('cm',75,20,0)

  oled.show()

  if distance_in_cm<15:
    for i in range(100):
      buzzer.init(freq=1850,duty=1000)
      sleep(0.2)
      buzzer.init(freq=1,duty=0)
      sleep(0.2)

      led1.on()
      sleep(0.1)
      led1.off()
      sleep(0.1)
  elif 15<= distance_in_cm<30:
    for i in range(100):
      buzzer.init(1750,duty=250)
      sleep(0.5)
      buzzer.init(freq=1,duty=0)
      sleep(0.5)

      led2.on()
      sleep(0.5)
      led2.off()
      sleep(0.5)
  elif 30<= distance_in_cm<50:
    for i in range(100):
      buzzer.init(freq=1500,duty=150)
      sleep(1)
      buzzer.init(freq=1,duty=0)
      sleep(1)

      led3.on()
      sleep(1)
      led3.off()
      sleep(1)
  else:
    buzzer.init(freq=1,duty=0)

  sleep(5)





while True:
  led1.on()
  sleep(0.1)
  led1.off()
  sleep(0.1)

  led2.on()
  sleep(0.1)
  led2.off()
  sleep(0.1)

  led3.on()
  sleep(0.1)
  led3.off()
  sleep(0.1)