//NIM : 2440023583
//Nama : Irenna Violla
//Judul Sistem : Pintu Kulkas Otomatis dengan Sensor Ultrasonik 
//dan Lampu Otomatis dengan Sensor LDR (ESP1)
//SENDING DATA TO THINGSPEAK

#include <WiFi.h>
#include <HTTPClient.h>
#include <LiquidCrystal.h>

const int echoPin = 4;
const int trigPin = 2;
const int ldrPin = 34;

long lastTime = 0;
long timerDelay = 100;

LiquidCrystal lcd(14, 27, 26, 25, 33, 32);

const char ssid[] = "Wokwi-GUEST";
const char password[]= "";

String serverName = "https://api.thingspeak.com/update?api_key=1NIR2UKT30OQMS2D&field1=0";

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
  pinMode(echoPin, INPUT);
  pinMode(trigPin, OUTPUT);

  WiFi.begin(ssid,password, 6);
  while(WiFi.status() != WL_CONNECTED){
    delay(500);
    Serial.print('-');
  }

  Serial.println("");
  Serial.print("System Connected");
  Serial.println(WiFi.localIP());

  lcd.begin(16,2);
  lcd.clear();
}

void loop() {
  if((millis() - lastTime) > timerDelay){
    if(WiFi.status() == WL_CONNECTED){
      digitalWrite(trigPin, LOW); //perintah untuk memastikan sensor ultrasonik belum memancarkan gelombang
      delayMicroseconds(2);
      digitalWrite(trigPin, HIGH); //sensor ultrasonik memancarkan gelombang ultrasoniknya
      delayMicroseconds(10); //durasi pancaran gelombang ultrasonik
      digitalWrite(trigPin, LOW); //perintah untuk menghentikan pancaran gelombang ultrasonik
      int durasiPantulan = pulseIn(echoPin, HIGH); //perintah untuk membaca jeda ketika gelombang dipancarkan oleh trigger kemudian diterima kembali oleh echo
      float jarak = durasiPantulan * 0.034 / 2; //rumus jarak dalam cm

      lcd.setCursor(0, 0); //set posisi karakter di lcd pada kolom 0, baris 0
      lcd.print("Jarak: "); 
      lcd.print(jarak); 
      lcd.print(" cm");

      int cahaya = analogRead(ldrPin); 
      
      lcd.setCursor(0, 1);
      lcd.print("Cahaya: ");
      lcd.print(cahaya);

      delay(100);
      sendData(jarak, cahaya);
    }
    else{
      Serial.println("Wifi Disconnected");
    }
    lastTime = millis();
  }
}

void sendData(int jarak, int cahaya){
  HTTPClient http; //instalasi HTTP Client

  Serial.print("Jarak : ");
  Serial.println(jarak);
  Serial.print("Cahaya : ");
  Serial.println(cahaya);

  String url = serverName + "&field1=" + jarak + "&field2=" + cahaya;

  http.begin(url.c_str()); // send HTTP Request/inisialisasi
  int httpResponseCode = http.GET(); //check status data

  if(httpResponseCode > 0){
    Serial.print("HTTP Response Code:");
    Serial.println(httpResponseCode);
  }
  else{
    Serial.print("Error Code");
    Serial.println(httpResponseCode);
  }
  http.end();
}