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


const char* ssid = "Wokwi-GUEST";
const char* password = ""; 
const char* thingSpeakApiKey = "99F2BQ6BXEU26MCM"; 
const int ThingSpeakChannelID = 2282512; 
const char* server = "api.thingspeak.com";

const float GAMMA = 0.7;
const float RL10 = 50;    


#define LDRanalog 34
#define LDRdigital 26
#define LED 18
WiFiClient client;

void setup() {
  Serial.begin(115200);
  pinMode(LED, OUTPUT); 
  connectToWiFi(); 
  WiFi.mode(WIFI_STA);
  ThingSpeak.begin(client);
}

void loop() {
  int nilaiDigital = digitalRead(LDRdigital);
  int nilaiADC = analogRead(LDRanalog);

  float voltage = nilaiADC * 5 / 4095.0;
  float resistance = 2000 * voltage / (1 - voltage / 5);
  float lux = pow(RL10 * 1e3 * pow(10, GAMMA) / resistance, (1 / GAMMA));

  Serial.print("Nilai Digital = ");
  Serial.println(nilaiDigital);
  Serial.print("Nilai ADC     = ");
  Serial.println(nilaiADC);
  Serial.print("Lux           = ");
  Serial.println(lux);
  Serial.print("Tegangan      = ");
  Serial.println(voltage);
  
  if (lux > 500) {
    digitalWrite(LED, HIGH);
  } else if (lux < 500) {
    digitalWrite(LED, LOW);
  } else {
    digitalWrite(LED, LOW);
  }

  if (WiFi.status() == WL_CONNECTED) {
    ThingSpeak.setField(1, lux);

    int httpCode = ThingSpeak.writeFields(ThingSpeakChannelID, thingSpeakApiKey); 

    if (httpCode == 200) {
      Serial.println("Data sent to ThingSpeak successfully."); 
    } else {
      Serial.println("Error sending data to ThingSpeak. HTTP code: " + String(httpCode));
    }
  } else {
    Serial.println("WiFi not connected. Reconnecting...");
    connectToWiFi(); 
  }

  delay(15000);
}

void connectToWiFi() {
  WiFi.begin(ssid, password); 
  while (WiFi.status() != WL_CONNECTED) { 
    delay(1000);
    Serial.println("Connecting to WiFi...");
  }
  Serial.println("WiFi connected.");
}