MODUL 26 (SPESIALIS IOT): PHP BACKEND INGEST DATA IOT

📌 META MODUL & PRASYARAT

• Bidang Spesialisasi: Backend API Engineering for IoT Data Ingestion.
• Target Pembaca: Pembelajar yang sudah menguasai Database Fundamentals (Modul 25).
• Learning Outcome:
• Memahami peran PHP Native Backend sebagai tempat penampungan (Ingest Engine) data sensor dari ESP32.
• Mampu membuat API Endpoint Receiver (/api/telemetry.php) berbasis PDO & Prepared Statements.
• Mampu memvalidasi API Key / Secret Token dari header HTTP request ESP32.
• Mampu mengeluarkan response JSON terstruktur untuk status balasan ke ESP32.
• Estimasi Waktu Belajar: 120 Menit.
• Tingkat Kesulitan: 🟢 Pemula - Menengah (Level 26 / 40).
• Prasyarat: Modul 25 (Database Fundamentals untuk IoT).

⚡ CHEAT SHEET KODE PHP INGEST RECEIVER API (api/telemetry.php)

<?php
declare(strict_types=1);
header('Content-Type: application/json');

// 1. Verifikasi HTTP Method (Hanya izinkan POST)
if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
    http_response_code(405);
    echo json_encode(['status' => 'error', 'message' => 'Method Not Allowed']);
    exit;
}

// 2. Verifikasi API Key Keamanan dari ESP32
$headers = getallheaders();
$apiKey = $headers['X-API-KEY'] ?? $_POST['api_key'] ?? '';

if ($apiKey !== 'Deeptech_Secret_Key_9988') {
    http_response_code(401);
    echo json_encode(['status' => 'error', 'message' => 'API Key Invalid or Missing']);
    exit;
}

// 3. Baca Payload Data JSON
$rawInput = file_get_contents('php://input');
$data = json_decode($rawInput, true);

$deviceUuid  = $data['device_uuid'] ?? '';
$temperature = (float)($data['temperature'] ?? 0);
$humidity    = (float)($data['humidity'] ?? 0);

if (empty($deviceUuid)) {
    http_response_code(400);
    echo json_encode(['status' => 'error', 'message' => 'device_uuid is required']);
    exit;
}

// 4. Simpan ke Database MySQL menggunakan PDO
try {
    $pdo = new PDO('mysql:host=127.0.0.1;dbname=esp_deeptech;charset=utf8mb4', 'root', '');
    $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

    $sql = "INSERT INTO telemetry_logs (device_uuid, temperature, humidity, created_at) 
            VALUES (:uuid, :temp, :hum, NOW())";
    $stmt = $pdo->prepare($sql);
    $stmt->execute([
        ':uuid' => $deviceUuid,
        ':temp' => $temperature,
        ':hum'  => $humidity
    ]);

    http_response_code(201);
    echo json_encode([
        'status' => 'success',
        'message' => 'Data telemetry berhasil disimpan!',
        'inserted_at' => date('Y-m-d H:i:s')
    ]);

} catch (PDOException $e) {
    http_response_code(500);
    echo json_encode(['status' => 'error', 'message' => 'Database error: ' . $e->getMessage()]);
}