📡 Membangun Jaringan Sensor LoRa: Telemetry & Monitoring

ESP32          SX1276 Module
─────          ─────────────
GPIO 5  (SCK)  ──→  SCK
GPIO 23 (MOSI) ──→  MOSI
GPIO 19 (MISO) ←──  MISO
GPIO 18 (NSS)  ──→  NSS  (CS)
GPIO 26 (RST)  ──→  RST
GPIO 34 (DIO0) ←──  DIO0 (Interrupt)
3.3V           ──→  VCC
GND            ──→  GND

#include <SPI.h>
#include <LoRa.h>
#include <DHT.h>

// ── Pin LoRa ──
#define LORA_SCK   5
#define LORA_MISO  19
#define LORA_MOSI  23
#define LORA_NSS   18
#define LORA_RST   26
#define LORA_DIO0  34

// ── Pin Sensor ──
#define DHT_PIN    4
#define DHT_TYPE   DHT22

// ── Konfigurasi LoRa ──
#define LORA_FREQ       920.0E6   // 920 MHz untuk Indonesia
#define LORA_SF         7         // Spreading Factor 7-12
#define LORA_BW         125E3     // Bandwidth 125 kHz
#define LORA_CR         5         // Coding Rate 4/5
#define LORA_TX_POWER   17        // TX Power dalam dBm (max 20)

// ── Variabel Global ──
DHT dht(DHT_PIN, DHT_TYPE);
unsigned long nodeId = 1001;
unsigned long packetCounter = 0;

void setup() {
  Serial.begin(115200);
  while (!Serial);
  Serial.println(F("=== LoRa Sender Node ==="));

  // Inisialisasi DHT sensor
  dht.begin();

  // Inisialisasi SPI dan LoRa
  SPI.begin(LORA_SCK, LORA_MISO, LORA_MOSI, LORA_NSS);
  LoRa.setPins(LORA_NSS, LORA_RST, LORA_DIO0);

  if (!LoRa.begin(LORA_FREQ)) {
    Serial.println(F("[ERROR] Gagal memulai LoRa!"));
    while (1);
  }

  // Konfigurasi parameter LoRa
  LoRa.setSpreadingFactor(LORA_SF);
  LoRa.setSignalBandwidth(LORA_BW);
  LoRa.setCodingRate4(LORA_CR);
  LoRa.setTxPower(LORA_TX_POWER);
  LoRa.enableCrc();

  Serial.println(F("[OK] LoRa terinisialisasi pada 920 MHz"));
  Serial.printf("[INFO] SF=%d, BW=%d kHz, CR=4/%d\n",
                LORA_SF, (int)(LORA_BW/1000), LORA_CR);
}

void loop() {
  // Baca sensor
  float suhu = dht.readTemperature();
  float kelembaban = dht.readHumidity();

  // Validasi pembacaan sensor
  if (isnan(suhu) || isnan(kelembaban)) {
    Serial.println(F("[WARN] Gagal membaca DHT22, retry..."));
    delay(2000);
    return;
  }

  // Bangun payload
  packetCounter++;
  String payload = buildPayload(suhu, kelembaban);

  // Kirim via LoRa
  Serial.printf("[TX] Paket #%lu: %s\n", packetCounter, payload.c_str());

  LoRa.beginPacket();
  LoRa.print(payload);
  LoRa.endPacket();

  Serial.printf("[TX] Terkirim! Suhu=%.1f°C, RH=%.1f%%\n", suhu, kelembaban);

  // Delay sebelum pengiriman berikutnya
  delay(30000);  // Kirim setiap 30 detik
}

String buildPayload(float suhu, float kelembaban) {
  // Format: NODE_ID|PACKET_NUM|SUHU|KELEMBABAN|RSSI
  String payload = "";
  payload += String(nodeId);
  payload += "|" + String(packetCounter);
  payload += "|" + String(suhu, 1);
  payload += "|" + String(kelembaban, 1);
  payload += "|" + String(millis() / 1000);
  return payload;
}

#include <SPI.h>
#include <LoRa.h>
#include <WiFi.h>
#include <WebServer.h>

// ── Pin LoRa ──
#define LORA_SCK   5
#define LORA_MISO  19
#define LORA_MOSI  23
#define LORA_NSS   18
#define LORA_RST   26
#define LORA_DIO0  34

// ── Konfigurasi WiFi ──
const char* WIFI_SSID = "NamaWiFi";
const char* WIFI_PASS = "PasswordWiFi";

// ── Konfigurasi LoRa ──
#define LORA_FREQ  920.0E6
#define LORA_SF    7

// ── Variabel Global ──
WebServer server(80);
String lastPayload = "";
String lastSenderInfo = "";
unsigned long rxCount = 0;

// ── Buffer data sensor (max 10 node) ──
struct SensorData {
  unsigned long nodeId;
  unsigned long packetNum;
  float suhu;
  float kelembaban;
  int rssi;
  unsigned long uptime;
  unsigned long lastUpdate;
};

SensorData nodes[10];
int nodeCount = 0;

void setup() {
  Serial.begin(115200);
  Serial.println(F("=== LoRa Gateway ==="));

  // Inisialisasi LoRa
  SPI.begin(LORA_SCK, LORA_MISO, LORA_MOSI, LORA_NSS);
  LoRa.setPins(LORA_NSS, LORA_RST, LORA_DIO0);

  if (!LoRa.begin(LORA_FREQ)) {
    Serial.println(F("[ERROR] Gagal memulai LoRa!"));
    while (1);
  }
  LoRa.setSpreadingFactor(LORA_SF);
  LoRa.setSignalBandwidth(125E3);
  LoRa.enableCrc();

  // Koneksi WiFi
  WiFi.begin(WIFI_SSID, WIFI_PASS);
  Serial.printf("[WiFi] Menghubungkan ke %s", WIFI_SSID);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.printf("\n[WiFi] Terhubung! IP: %s\n",
                WiFi.localIP().toString().c_str());

  // Setup Web Server
  server.on("/", handleRoot);
  server.on("/api/data", handleApiData);
  server.begin();
  Serial.println("[HTTP] Web server aktif di port 80");

  Serial.println(F("[OK] Gateway siap menerima data LoRa\n"));
}

void loop() {
  // Cek paket LoRa masuk
  int packetSize = LoRa.parsePacket();
  if (packetSize) {
    String incoming = "";
    while (LoRa.available()) {
      incoming += (char)LoRa.read();
    }

    int rssi = LoRa.packetRssi();
    float snr = LoRa.packetSnr();

    rxCount++;
    Serial.printf("[RX] #%lu | RSSI: %d dBm | SNR: %.1f dB\n",
                  rxCount, rssi, snr);
    Serial.printf("[RX] Payload: %s\n", incoming.c_str());

    // Parse payload
    parsePayload(incoming, rssi);
  }

  // Handle HTTP client
  server.handleClient();
}

void parsePayload(String payload, int rssi) {
  // Format: NODE_ID|PACKET_NUM|SUHU|KELEMBABAN|UPTIME
  int idx = 0;
  String parts[5];
  int partCount = 0;

  while (payload.indexOf('|') >= 0 && partCount < 5) {
    idx = payload.indexOf('|');
    parts[partCount++] = payload.substring(0, idx);
    payload = payload.substring(idx + 1);
  }
  if (partCount < 5) parts[partCount++] = payload;

  if (partCount >= 5) {
    unsigned long nId = parts[0].toInt();
    SensorData* node = findOrCreateNode(nId);
    node->nodeId       = nId;
    node->packetNum    = parts[1].toInt();
    node->suhu         = parts[2].toFloat();
    node->kelembaban   = parts[3].toFloat();
    node->uptime       = parts[4].toInt();
    node->rssi         = rssi;
    node->lastUpdate   = millis();

    lastPayload = payload;
    Serial.printf("[PARSE] Node %lu: Suhu=%.1f°C RH=%.1f%% RSSI=%d\n",
                  nId, node->suhu, node->kelembaban, rssi);
  }
}

SensorData* findOrCreateNode(unsigned long nodeId) {
  for (int i = 0; i < nodeCount; i++) {
    if (nodes[i].nodeId == nodeId) return &nodes[i];
  }
  if (nodeCount < 10) {
    nodes[nodeCount].nodeId = nodeId;
    return &nodes[nodeCount++];
  }
  return &nodes[0];
}

void handleRoot() {
  String html = "<html><body style='font-family:monospace;background:#111;color:#0f0;padding:20px'>";
  html += "<h1>📡 LoRa Gateway Dashboard</h1>";
  html += "<p>Total diterima: " + String(rxCount) + " paket</p>";
  html += "<hr>";
  for (int i = 0; i < nodeCount; i++) {
    html += "<div style='margin:10px 0;padding:10px;border:1px solid #333'>";
    html += "<b>Node " + String(nodes[i].nodeId) + "</b><br>";
    html += "Suhu: " + String(nodes[i].suhu, 1) + " °C<br>";
    html += "Kelembaban: " + String(nodes[i].kelembaban, 1) + " %<br>";
    html += "RSSI: " + String(nodes[i].rssi) + " dBm<br>";
    html += "</div>";
  }
  html += "</body></html>";
  server.send(200, "text/html", html);
}

void handleApiData() {
  String json = "{\"nodes\":[";
  for (int i = 0; i < nodeCount; i++) {
    if (i > 0) json += ",";
    json += "{\"id\":" + String(nodes[i].nodeId);
    json += ",\"suhu\":" + String(nodes[i].suhu, 1);
    json += ",\"kelembaban\":" + String(nodes[i].kelembaban, 1);
    json += ",\"rssi\":" + String(nodes[i].rssi);
    json += ",\"uptime\":" + String(nodes[i].uptime) + "}";
  }
  json += "],\"total_rx\":" + String(rxCount) + "}";
  server.send(200, "application/json", json);
}

#include <PubSubClient.h>

// ── Konfigurasi MQTT ──
const char* MQTT_SERVER = "broker.hivemq.com";
const int   MQTT_PORT   = 1883;
const char* MQTT_TOPIC  = "iothub/lora/nodes/";

WiFiClient espClient;
PubSubClient mqttClient(espClient);

void mqttConnect() {
  while (!mqttClient.connected()) {
    Serial.print("[MQTT] Menghubungkan...");
    String clientId = "lora-gw-" + String(random(0xffff), HEX);

    if (mqttClient.connect(clientId.c_str())) {
      Serial.println(" terhubung!");
    } else {
      Serial.printf(" gagal (rc=%d). Retry...\n", mqttClient.state());
      delay(5000);
    }
  }
}

void publishSensorData(SensorData &node) {
  // Publish ke topik per-node
  String topic = String(MQTT_TOPIC) + String(node.nodeId);

  String json = "{";
  json += "\"suhu\":" + String(node.suhu, 1) + ",";
  json += "\"kelembaban\":" + String(node.kelembaban, 1) + ",";
  json += "\"rssi\":" + String(node.rssi) + ",";
  json += "\"uptime\":" + String(node.uptime) + ",";
  json += "\"timestamp\":" + String(millis());
  json += "}";

  mqttClient.publish(topic.c_str(), json.c_str());
  Serial.printf("[MQTT] Published ke %s\n", topic.c_str());
}

#define SLEEP_DURATION  300  // 5 menit dalam detik
#define uS_TO_S_FACTOR  1000000ULL

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

  // Nonaktifkan WiFi & Bluetooth untuk hemat daya
  WiFi.mode(WIFI_OFF);
  btStop();

  // ... inisialisasi LoRa dan baca sensor ...
  // ... kirim data ...

  Serial.printf("[SLEEP] Tidur selama %d detik...\n", SLEEP_DURATION);
  Serial.flush();

  // Masuk deep sleep
  esp_sleep_enable_timer_wakeup(SLEEP_DURATION * uS_TO_S_FACTOR);
  esp_deep_sleep_start();
}

void loop() {
  // Tidak akan pernah sampai sini saat deep sleep
  // Semua logic dijalankan di setup() lalu sleep
}