#include <WiFi.h>
#include <ThingSpeak.h>
#include <LiquidCrystal_I2C.h>



#define ldrPin 2
const float gama = 0.7;
const float rl10 = 50;
LiquidCrystal_I2C lcd(0x27,16,2);
const int echoPin = 2;
const int trigPin = 15;
//define sound speed in cm/uS
#define SOUND_SPEED 0.034
#define relay 2

long duration;
float distanceCm;


void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(trigPin, OUTPUT); // Sets the trigPin as an Output
  pinMode(echoPin, INPUT); // Sets the echoPin as an Input
  pinMode(ldrPin, INPUT);
  pinMode(relay, OUTPUT);
  lcd.init();
}

void loop() {
  // put your main code here, to run repeatedly:
  delay(10); // this speeds up the simulation
  int nilaiLDR = analogRead(ldrPin);
  nilaiLDR = map(nilaiLDR, 4095, 0, 1024, 0); //mengubah nilai pembacaan sensor LDR dari nilai ADC arduino menjadi nilai ADC ESP32
  float voltase = nilaiLDR / 1024.*5;
  float resistansi = 2000 * voltase / (1-voltase/5);
  float kecerahan = pow(rl10*1e3*pow(10,gama)/resistansi,(1/gama));
  Serial.print("Kecerahan = ");
  Serial.println(kecerahan);
  delay(1000);
  
  // Clears the trigPin
  digitalWrite(trigPin, LOW);
  delay(1000);

  // Sets the trigPin on HIGH state for 10 micro seconds
  digitalWrite(trigPin, HIGH);
  delay(1000);
  digitalWrite(trigPin, LOW);
  // Reads the echoPin, returns the sound wave travel time in microseconds
  duration = pulseIn(echoPin, HIGH);
  
  // Calculate the distance
  distanceCm = duration * SOUND_SPEED/2;
  Serial.print("Distance (cm): ");
  Serial.println(distanceCm);
  lcd.setCursor(0,0);
  lcd.print("Distance: ");
  lcd.print(distanceCm);
  lcd.setCursor(0,1);
  lcd.print("kecerahan: ");
  lcd.print(kecerahan);

  if( kecerahan<50 && distanceCm > 100){
    digitalWrite(relay, HIGH);
  }else if(kecerahan>50 && distanceCm > 100){
    digitalWrite(relay, HIGH);
  }else if(kecerahan>50 && distanceCm < 100){
    digitalWrite(relay, LOW);
  }else if(kecerahan<50 && distanceCm < 100){
    digitalWrite(relay, LOW);
  }
}