print("This is the program for Car Reverse Sensor SYSTEM")
print("BY ANNISHA FOR IOT")

# STEP 1 : IMPORT MODULES OR LIBRARY
from machine import Pin 
from machine import I2C
from machine import PWM
from time import sleep
import ssd1306
import hcsr04

# STEP 2: DECLARE CONNECTION

# ESP32 Pin assignment
i2c = I2C(0, scl=Pin(22), sda=Pin(21))

ledR = Pin(15, Pin.OUT)
ledG = Pin(2, Pin.OUT)
BUZZ_Pin = Pin(14, Pin.OUT)

oled_width = 128
oled_height = 64
oled = ssd1306.SSD1306_I2C(oled_width, oled_height, i2c)

# STEP 2.2 : DECLARE THE CONNECTION FOR ULTRASONIC SENSOR
distanceSensor = hcsr04.HCSR04(trigger_pin=17, echo_pin=16)

print("Social Distancing System")

while True:
    # ULTRASONIC PART 
    oled.fill(0)
    oled.text("DISTANCE OF ", 5, 5)
    oled.text("PERSON : ", 5, 15)

    cm = distanceSensor.distance_cm()
    cm_string = str("{:.2f}".format(cm))
    oled.text(cm_string + "cm", 5, 30)

    if cm > 200:
        oled.text("Safe Distance", 5, 45)
        ledG.on()
        sleep(0.5)
        ledG.off()
    else:
        oled.text("Too Close!", 5, 45)
        buzzer = PWM(BUZZ_Pin, freq=1000, duty=512)  # Turn on buzzer
        ledR.on()  # Turn on red LED
        sleep(0.5)
        buzzer.deinit()  # Turn off buzzer
        ledR.off()  # Turn off red LED

    sleep(0.1)
    oled.show()