//design a reverse car parking in which the ultrasocinc sensor will measure 
// distance between rear of car and wall of parking and accordingly led pwm brightness changes
#include <ESP32Servo.h>
const int trigPin = 12;
const int echoPin = 13;
long duration;
int distance;
const int rled = 14;

void setup() {
  pinMode(rled, OUTPUT); 
  Serial.begin(115200);
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
}

void loop() {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  duration = pulseIn(echoPin, HIGH);
  distance = duration * 0.034 / 2;
  

  int brightness = map(distance, 0, 399, 1023, 0);
  int percentbright = map(brightness,0,1023,0,100);

  Serial.print("Distance=");
  Serial.print(distance);
  Serial.print(" BRIGHTNESS OF LED ");
  Serial.print(percentbright);
  Serial.println("%");
    
  analogWrite(rled,brightness);
  
  delay(1000);
}