Monitoring Suhu dan Kelembapan ESP32 DHT11 ke AhrarTech IoT via HTTP API

Source Code

Berikut adalah source code ESP32 + DHT11 untuk membaca data suhu dan kelembapan, kemudian mengirimkan data tersebut ke AhrarTech IoT melalui HTTP API.

Sebelum meng-upload program ke ESP32, sesuaikan terlebih dahulu nama WiFi, password WiFi, Device Token, dan interval pengiriman data.

#include <WiFi.h>
#include <WiFiClientSecure.h>
#include <HTTPClient.h>
#include <DHT.h>

// ==============================
// DHT11
// ==============================
#define DHTPIN 4
#define DHTTYPE DHT11

DHT dht(DHTPIN, DHTTYPE);

// ==============================
// WIFI
// ==============================
const char* WIFI_SSID = "NAMA_WIFI_ANDA";
const char* WIFI_PASSWORD = "PASSWORD_WIFI_ANDA";

// ==============================
// AHRAR IOT
// ==============================
const char* API_URL =
  "https://iot.ahrartech.com/api/v1/device/telemetry";

const char* DEVICE_TOKEN =
  "DEVICE_TOKEN_ANDA";

// Interval kirim data: 10 detik
const unsigned long SEND_INTERVAL = 10000;

unsigned long lastSend = 0;

// ==============================
// CONNECT WIFI
// ==============================
void connectWiFi() {

  Serial.print("Connecting to WiFi");

  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);

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

  Serial.println();
  Serial.println("WiFi connected");

  Serial.print("IP Address: ");
  Serial.println(WiFi.localIP());
}

// ==============================
// SEND TELEMETRY
// ==============================
void sendTelemetry(float suhu, float kelembapan) {

  if (WiFi.status() != WL_CONNECTED) {
    Serial.println("WiFi disconnected");
    connectWiFi();
  }

  WiFiClientSecure client;
  client.setInsecure();

  HTTPClient http;

  Serial.println();
  Serial.println("-----------------------------");
  Serial.println("Sending telemetry...");

  if (!http.begin(client, API_URL)) {
    Serial.println("Failed to connect to API");
    return;
  }

  // ==============================
  // HEADER
  // ==============================
  http.addHeader(
    "Content-Type",
    "application/json"
  );

  String authorization = "Bearer ";
  authorization += DEVICE_TOKEN;

  http.addHeader(
    "Authorization",
    authorization
  );

  // ==============================
  // JSON PAYLOAD
  // ==============================
  String payload = "{";

  payload += "\"suhu\":";
  payload += String(suhu, 1);

  payload += ",";

  payload += "\"kelembapan\":";
  payload += String(kelembapan, 1);

  payload += "}";

  Serial.print("Payload: ");
  Serial.println(payload);

  // ==============================
  // HTTP POST
  // ==============================
  int httpCode = http.POST(payload);

  Serial.print("HTTP Status: ");
  Serial.println(httpCode);

  if (httpCode > 0) {

    String response = http.getString();

    Serial.print("Response: ");
    Serial.println(response);

    if (httpCode >= 200 && httpCode < 300) {
      Serial.println("Telemetry sent successfully");
    } else {
      Serial.println("Server returned an error");
    }

  } else {

    Serial.print("HTTP error: ");
    Serial.println(
      http.errorToString(httpCode)
    );
  }

  http.end();
}

// ==============================
// SETUP
// ==============================
void setup() {

  Serial.begin(115200);

  delay(1000);

  Serial.println();
  Serial.println("=============================");
  Serial.println("Ahrar IoT - ESP32 + DHT11");
  Serial.println("=============================");

  dht.begin();

  connectWiFi();
}

// ==============================
// LOOP
// ==============================
void loop() {

  if (millis() - lastSend >= SEND_INTERVAL) {

    lastSend = millis();

    // ==============================
    // READ SENSOR
    // ==============================
    float kelembapan = dht.readHumidity();
    float suhu = dht.readTemperature();

    // ==============================
    // VALIDATION
    // ==============================
    if (
      isnan(suhu) ||
      isnan(kelembapan)
    ) {

      Serial.println("Failed to read DHT11!");
      return;
    }

    // ==============================
    // SERIAL OUTPUT
    // ==============================
    Serial.println();
    Serial.println("DHT11 Data");

    Serial.print("Suhu       : ");
    Serial.print(suhu, 1);
    Serial.println(" °C");

    Serial.print("Kelembapan : ");
    Serial.print(kelembapan, 1);
    Serial.println(" %");

    // ==============================
    // SEND TO AHRAR IOT
    // ==============================
    sendTelemetry(
      suhu,
      kelembapan
    );
  }
}

Parameter yang Perlu Diubah

Sebelum program di-upload ke ESP32, ubah konfigurasi berikut:

const char* WIFI_SSID = "NAMA_WIFI_ANDA";
const char* WIFI_PASSWORD = "PASSWORD_WIFI_ANDA";

const char* DEVICE_TOKEN =
  "DEVICE_TOKEN_ANDA";

const unsigned long SEND_INTERVAL = 10000;

Keterangan:

• WIFI_SSID → nama jaringan WiFi.
• WIFI_PASSWORD → password WiFi.
• DEVICE_TOKEN → token device yang diperoleh dari AhrarTech IoT.
• SEND_INTERVAL → interval pengiriman data dalam milidetik. Nilai 10000 berarti data dikirim setiap 10 detik.

Pastikan sebelum mulai:

• ESP32 board package: ESP32 by Espressif Systems
• DHT library: DHT sensor library by Adafruit
• Dependency: Adafruit Unified Sensor
• Driver USB ESP32 sudah terpasang
• Board dan Port di Arduino IDE sudah benar