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

#define TRIG_PIN 16 // Pin TRIG
#define ECHO_PIN 4  // Pin ECHO
#define THINKSPEAK_API_KEY "YN990QJE4JRX9AGR" // API Key ThinkSpeak
#define THINKSPEAK_CHANNEL_ID 2574689 // ID Channel ThinkSpeak

const char* ssid = "Wokwi-GUEST";           // SSID WiFi
const char* password = "";  // Password WiFi
const char* server = "api.thingspeak.com";
float distance=0;
float duration=0;

WiFiClient client;
Ultrasonic ultrasonic(TRIG_PIN, ECHO_PIN);

void setup() {
  Serial.begin(9600);
  Serial.println("Monitoring Sensor");
  connectToWiFi();
}

void loop() {
 // delay(200); // Tunggu 2 detik sebelum membaca sensor
 // unsigned int distance = ultrasonic.read(CM); // Baca jarak dari sensor
  digitalWrite(TRIG_PIN,LOW);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN,HIGH);
  duration = pulseIn(ECHO_PIN,HIGH);
  distance =( 0.017 * duration);

  if (sendDataToThingSpeak(distance)) {
    Serial.println("Data terkirim ke ThingSpeak");
  } else {
    Serial.println("Gagal mengirim data ke ThingSpeak");
  }

  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");

  delay(10000); // Tunggu 10 detik sebelum membaca sensor lagi
}

void connectToWiFi() {
  Serial.print("Connecting to WiFi");
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("\nWiFi connected");
}

bool sendDataToThingSpeak(unsigned int distance) {
  if (!client.connect(server, 80)) {
    Serial.println("Gagal terhubung ke server ThingSpeak");
    return false;
  }

  String postStr = "api_key=";
  postStr += THINKSPEAK_API_KEY;
  postStr += "&field1=";
  postStr += String(distance);
  postStr += "\r\n\r\n";

  String headers = "POST /update HTTP/1.1\n";
  headers += "Host: api.thingspeak.com\n";
  headers += "Connection: close\n";
  headers += "X-THINGSPEAKAPIKEY: " + String(THINKSPEAK_API_KEY) + "\n";
  headers += "Content-Type: application/x-www-form-urlencoded\n";
  headers += "Content-Length: ";
  headers += String(postStr.length());
  headers += "\n\n";

  client.print(headers);
  client.print(postStr);
  client.stop();
  
  return true;
}