ESP32 MQTT - Mosquitto

#include <WiFi.h>
#include <PubSubClient.h>
#include <ModbusMaster.h>
#include <SoftwareSerial.h>

#define MAX485_RE_NEG  5
#define MAX485_DE      4
#define SSERIAL_RX_PIN 16
#define SSERIAL_TX_PIN 17

#define NUM_SENSORS 2
#define TEMP_SENSOR 0
#define HUM_SENSOR 1

const char* ssid = "vivo V29";
const char* password = "Nabila041185";

const char* mqtt_server = "test.mosquitto.org";
const char* mqtt_topic_temp = "nabila/suhu";
const char* mqtt_topic_hum = "nabila/kelembapan";
const char* mqtt_topic_pred = "nabila/prediksi";
const char *mqtt_username = "";
const char *mqtt_password = "";
const int mqtt_port = 1883;

const int led1Pin = 13;
const int led2Pin = 12;
const int led3Pin = 14;
const int led4Pin = 27;

SoftwareSerial RS485Serial(SSERIAL_RX_PIN, SSERIAL_TX_PIN);
ModbusMaster node;
WiFiClient espClient;
PubSubClient client(espClient);

uint16_t sensorAddresses[NUM_SENSORS] = {0x0001, 0x0002};
float sensorData[NUM_SENSORS];

void preTransmission() {
  digitalWrite(MAX485_RE_NEG, 1);
  digitalWrite(MAX485_DE, 1);
}

void postTransmission() {
  digitalWrite(MAX485_RE_NEG, 0);
  digitalWrite(MAX485_DE, 0);
}

void setup() {
  pinMode(MAX485_RE_NEG, OUTPUT);
  pinMode(MAX485_DE, OUTPUT);
  digitalWrite(MAX485_RE_NEG, 0);
  digitalWrite(MAX485_DE, 0);

  Serial.begin(9600);
  RS485Serial.begin(9600);

  node.begin(1, RS485Serial);
  node.preTransmission(preTransmission);
  node.postTransmission(postTransmission);

  WiFi.begin(ssid, password);
  while (!WiFi.isConnected()) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.println("WiFi terhubung");

  client.setServer(mqtt_server, mqtt_port);
}

void loop() {
  if (!client.connected()) {
    connect_mqtt();
  }

  for (int i = 0; i < NUM_SENSORS; i++) {
    uint8_t result = node.readInputRegisters(sensorAddresses[i], 1);

    if (result == node.ku8MBSuccess) {
      sensorData[i] = float(node.getResponseBuffer(0) / 10.00F);
    } else {
      delay(1000);
      return;
    }
  }

  send_mqtt(mqtt_topic_temp, sensorData[TEMP_SENSOR]);
  send_mqtt(mqtt_topic_hum, sensorData[HUM_SENSOR]);

  String prediction = analyze_and_predict(sensorData[TEMP_SENSOR], sensorData[HUM_SENSOR]);
  client.publish(mqtt_topic_pred, prediction.c_str());


  if (prediction.indexOf("panas") != -1 || prediction.indexOf("hujan") != -1) {       //  <--- Control LEDs based on prediction
    digitalWrite(led1Pin, HIGH);
    digitalWrite(led2Pin, HIGH);
    digitalWrite(led3Pin, LOW);
    digitalWrite(led4Pin, LOW);
  } else {
    digitalWrite(led1Pin, LOW);
    digitalWrite(led2Pin, LOW);
    digitalWrite(led3Pin, HIGH);
    digitalWrite(led4Pin, HIGH);
  }

  delay(2000);
}

void connect_mqtt() {
  while (!client.connected()) {
    Serial.println("Connecting to MQTT...");
    if (client.connect("ESP32Client", mqtt_username, mqtt_password)) {
      Serial.println("Connected to MQTT broker");
      // Subscribe to topics here
    } else {
      Serial.print("Failed, rc=");
      Serial.print(client.state());
      Serial.println(" Retrying in 5 seconds...");
      delay(5000);
    }
  }
}

void send_mqtt(const char* topic, float value) {
  char buffer[10];
  dtostrf(value, 4, 2, buffer);
  client.publish(topic, buffer);
}

String analyze_and_predict(float temp_value, float hum_value) {
  if (temp_value > 30) {
    return "Cuaca panas, kemungkinan tidak hujan.";
  } else if (hum_value > 70) {
    return "Kelembapan tinggi, potensi hujan.";
  } else {
    return "Cuaca normal, tidak ada perubahan signifikan.";
  }
}