print("REVERSE PARKING SENSOR!!!")

#IMPORT MODULES / LIBRARY

import hcsr04    #ultrasonic sensor
import ssd1306  #import oled
from utime import sleep
from machine import SoftI2C, Pin,   PWM     #PWM = pulse width modulation

#ULTRASONIC SENSOR, TO CREATE THE OBJECT

ultrasonic_sensor = hcsr04.HCSR04(trigger_pin=13, echo_pin=27, echo_timeout_us=500*2*30)

#OLED SET UP

i2c_oleddisplay=SoftI2C(scl=Pin(22),sda=Pin(21))
oled_width=128
oled_height=64

#USE OOP TO CREATE THE OBJECT

oled=ssd1306.SSD1306_I2C(oled_width,oled_height,i2c_oleddisplay)

#BUZZER, DECLARE/CREATE THE CONNECTION
buzzer=PWM(Pin(23),Pin.OUT)

#TEST ULTRASONIC SENSOR, BUZZER AND OLED

while True:
    distance_cm=ultrasonic_sensor.distance_cm
    distance_mm=ultrasonic_sensor.distance_mm

    print("AN OBJECT IS DETECTED WITHIN : ",distance_cm, 'cm')
    print("AN OBJECT IS DETECTED WITHIN : ",distance_mm, 'mm')

    #TO DISPLAY THE DISTANCE IN OLED 
    oled.fill(1)
    oled.text('OBJECT DETECTED',3,0,1 )
    oled.text(str( distance_cm), 0,20,1)
    oled.text('cm',80,20,1)
    oled.text(str( distance_mm), 0,40,1)
    oled.text('mm',80,40,1)
    
    oled.show()

    #TO DETERMINE THE DISTANCE 50CM OR 150CM
    if distance_cm<50:
        for i in range(10):
            buzzer.init(freq=1703, duty=400)
            sleep(0.5)
            buzzer.init(freq=1, duty=400)
            sleep(0.5)

    elif 50 <= distance_cm<150:
        for i in range(10):
            buzzer.init(freq=1703, duty=400)
            sleep(0.1)
            buzzer.init(freq=1, duty=400)
            sleep(0.1)
    else :
        buzzer.init(freq=1, duty=0)
        sleep(5)