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

// ================= LCD =================
LiquidCrystal_I2C lcd(0x27, 16, 2);

// ================= WIFI =================
const char* ssid = "Wokwi-GUEST";
const char* password = "";

// ================= ThingSpeak =================
unsigned long channelID = 3279211;       // Ganti channel ID
const char* writeAPIKey = "7X0CCSJVKZREB2IL";    // Ganti Write API Key

WiFiClient client;

// ================= Ultrasonic =================
#define TRIG 5
#define ECHO 18

long durasi;
float jarak;

void setup() {
  Serial.begin(115200);

  pinMode(TRIG, OUTPUT);
  pinMode(ECHO, INPUT);

  lcd.init();
  lcd.backlight();

  // Koneksi WiFi
  lcd.setCursor(0,0);
  lcd.print("Connecting WiFi");
  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  lcd.clear();
  lcd.print("WiFi Connected");
  delay(1500);

  ThingSpeak.begin(client);
}

void loop() {
  // Trigger ultrasonic
  digitalWrite(TRIG, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG, LOW);

  durasi = pulseIn(ECHO, HIGH);
  jarak = durasi * 0.034 / 2;

  // ================= LCD =================
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("Jarak:");
  lcd.print(jarak);
  lcd.print(" cm");

  // ================= Kirim ke ThingSpeak =================
  ThingSpeak.setField(1, jarak);
  int x = ThingSpeak.writeFields(channelID, writeAPIKey);

  if(x == 200){
    Serial.println("Data terkirim ke ThingSpeak");
    lcd.setCursor(0,1);
    lcd.print("Upload OK");
  } else {
    Serial.println("Gagal kirim");
    lcd.setCursor(0,1);
    lcd.print("Upload Gagal");
  }

  // Delay minimal ThingSpeak
  delay(15000);
}