บทความ: สร้างระบบติดตามพาหนะด้วย ESP32 4G LTE GPS และ MQTT

/*
 * ESP32 4G LTE GPS Vehicle Tracker
 * ส่งข้อมูล GPS ผ่าน MQTT ไปยัง Dashboard
 *
 * Hardware: ESP32 + SIM7600 (4G) + NEO-6M (GPS)
 * Author: CynoIoT
 * Date: March 2026
 */

#include <TinyGsmClient.h>
#include <PubSubClient.h>
#include <TinyGPS++.h>

// ==================== การตั้งค่า PIN ====================
// 4G Module (SIM7600)
#define SerialAT Serial1
#define PIN_DTR       25
#define PIN_TX        4
#define PIN_RX        2

// GPS Module (NEO-6M)
#define SerialGPS Serial2
#define GPS_RX       16
#define GPS_TX       17

// LED Status
#define LED_PIN       2

// ==================== การตั้งค่า MQTT ====================
const char* broker = "broker.hivemq.com";  // MQTT Broker
const int mqtt_port = 1883;
const char* topic = "cynoiot/vehicle/tracker";  // Topic หลัก

// Device ID (เปลี่ยนเป็น ID ของคุณ)
const char* device_id = "VEHICLE_001";

// ==================== การตั้งค่า APN ====================
// แก้ไขตาม SIM Card ที่ใช้
const char* apn = "internet";      // AIS: internet, DTAC: www.dtac.co.th
const char* user = "";
const char* pass = "";

// ==================== Objects ====================
TinyGsm modem(SerialAT);
TinyGsmClient client(modem);
PubSubClient mqtt(client);
TinyGPSPlus gps;

// ==================== ตัวแปร ====================
unsigned long lastMsg = 0;
const long interval = 5000;  // ส่งข้อมูลทุก 5 วินาที

void setup() {
  Serial.begin(115200);
  Serial.println(F("\n🚗 ESP32 Vehicle Tracker Starting..."));

  // ตั้งค่า LED
  pinMode(LED_PIN, OUTPUT);
  blinkLED(3);

  // เริ่มต้น GPS
  SerialGPS.begin(9600, SERIAL_8N1, GPS_RX, GPS_TX);
  Serial.println(F("✅ GPS Module initialized"));

  // เริ่มต้น 4G Module
  SerialAT.begin(115200, SERIAL_8N1, PIN_RX, PIN_TX);

  Serial.println(F("📡 Initializing 4G Module..."));
  delay(3000);

  // รีเซ็ต Module
  if (!modem.restart()) {
    Serial.println(F("❌ Failed to restart modem"));
    return;
  }

  // เชื่อมต่อเครือข่าย
  Serial.println(F("🔌 Waiting for network..."));
  if (!modem.waitForNetwork()) {
    Serial.println(F("❌ Network failed"));
    return;
  }

  if (!modem.gprsConnect(apn, user, pass)) {
    Serial.println(F("❌ GPRS failed"));
    return;
  }

  Serial.println(F("✅ Connected to 4G Network!"));
  Serial.print(F("📶 Signal: "));
  Serial.println(modem.getSignalQuality());

  // ตั้งค่า MQTT
  mqtt.setServer(broker, mqtt_port);
}

void loop() {
  // อ่านข้อมูล GPS
  while (SerialGPS.available() > 0) {
    gps.encode(SerialGPS.read());
  }

  // ส่งข้อมูลทุก interval
  unsigned long now = millis();
  if (now - lastMsg >= interval) {
    lastMsg = now;

    if (gps.location.isValid()) {
      sendData();
    } else {
      Serial.println(F("⏳ Waiting for GPS fix..."));
    }
  }

  // รักษาการเชื่อมต่อ MQTT
  if (!mqtt.connected()) {
    reconnectMQTT();
  }
  mqtt.loop();
}

void sendData() {
  // สร้าง JSON Payload
  String payload = "{";
  payload += "\"device_id\":\"" + String(device_id) + "\",";
  payload += "\"latitude\":" + String(gps.location.lat(), 6) + ",";
  payload += "\"longitude\":" + String(gps.location.lng(), 6) + ",";
  payload += "\"altitude\":" + String(gps.altitude.meters()) + ",";
  payload += "\"speed\":" + String(gps.speed.kmph()) + ",";
  payload += "\"heading\":" + String(gps.course.deg()) + ",";
  payload += "\"satellites\":" + String(gps.satellites.value()) + ",";
  payload += "\"timestamp\":" + String(now);
  payload += "}";

  // ส่งผ่าน MQTT
  Serial.print(F("📤 Sending: "));
  Serial.println(payload);

  if (mqtt.publish(topic, payload.c_str())) {
    Serial.println(F("✅ Data sent successfully"));
    blinkLED(1);
  } else {
    Serial.println(F("❌ Failed to send data"));
  }
}

void reconnectMQTT() {
  while (!mqtt.connected()) {
    Serial.print(F("🔗 Connecting to MQTT..."));

    // สร้าง Client ID แบบสุ่ม
    String clientId = "ESP32Client-";
    clientId += String(random(0xffff), HEX);

    if (mqtt.connect(clientId.c_str())) {
      Serial.println(F("✅ Connected"));
      mqtt.publish(topic, "connected");  // แจ้งสถานะ
    } else {
      Serial.print(F("❌ Failed, rc="));
      Serial.print(mqtt.state());
      Serial.println(F(" retrying in 5 seconds"));
      delay(5000);
    }
  }
}

void blinkLED(int times) {
  for (int i = 0; i < times; i++) {
    digitalWrite(LED_PIN, HIGH);
    delay(100);
    digitalWrite(LED_PIN, LOW);
    delay(100);
  }
}

<!DOCTYPE html>
<html>
<head>
    <title>Vehicle Tracker Dashboard</title>
    <link rel="stylesheet" href="https://unpkg.com/leaflet@1.9.4/dist/leaflet.css"/>
    <script src="https://unpkg.com/leaflet@1.9.4/dist/leaflet.js"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/paho-mqtt/1.0.1/mqttws31.min.js"></script>
    <style>
        #map { height: 600px; }
        body { font-family: Arial, sans-serif; margin: 0; padding: 20px; }
        .info { background: white; padding: 15px; border-radius: 5px; margin-bottom: 20px; }
    </style>
</head>
<body>
    <h1>🚗 Vehicle Tracker</h1>
    <div class="info">
        <strong>สถานะ:</strong> <span id="status">Connecting...</span><br>
        <strong>Latitude:</strong> <span id="lat">-</span><br>
        <strong>Longitude:</strong> <span id="lng">-</span><br>
        <strong>Speed:</strong> <span id="speed">-</span> km/h
    </div>
    <div id="map"></div>

    <script>
        // เริ่มต้นแผนที่
        var map = L.map('map').setView([13.7563, 100.5018], 13);
        L.tileLayer('https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png', {
            attribution: '© OpenStreetMap'
        }).addTo(map);

        // Marker สำหรับรถ
        var marker = L.marker([13.7563, 100.5018]).addTo(map);

        // เชื่อมต่อ MQTT
        var client = new Paho.MQTT.Client("broker.hivemq.com", 8000, "webclient");

        client.onConnectionLost = function(response) {
            document.getElementById('status').innerText = "Disconnected";
        };

        client.onMessageArrived = function(message) {
            var data = JSON.parse(message.payloadString);

            // อัปเดตข้อมูล
            document.getElementById('status').innerText = "Connected";
            document.getElementById('lat').innerText = data.latitude;
            document.getElementById('lng').innerText = data.longitude;
            document.getElementById('speed').innerText = data.speed;

            // ย้าย Marker ไปตำแหน่งใหม่
            var newLatLng = new L.LatLng(data.latitude, data.longitude);
            marker.setLatLng(newLatLng);
            map.setView(newLatLng, 16);
        };

        // เชื่อมต่อ
        client.connect({
            onSuccess: function() {
                document.getElementById('status').innerText = "Connected";
                client.subscribe("cynoiot/vehicle/tracker");
            }
        });
    </script>
</body>
</html>