ESP32 MQTT & MQTT Box Control ESP32 build LED on or off

 ESP32 MQTT & MQTT Box  Control ESP32 build LED on or off

系統圖

MQTT Box 設定的畫面

const char *mqtt_server = "broker.mqtt-dashboard.com";

const char *mqtt_username = "alex9ufo";

const char *mqtt_password = "public";

const int mqtt_port = 1883;

const char *topic1 = "alex9ufo/ESP32/LED_output";

const char *topic2 = "alex9ufo/ESP32/LED_status";

ESP32 Arduino 程式

#include <WiFi.h>

#include <PubSubClient.h>

// Replace the next variables with your SSID/Password combination

//const char* ssid = "XXXXXXXXX";

//const char* password = "XXXXXXXXX";

const char* ssid = "alex9ufo"; // Enter your Wi-Fi name

const char* password = "alex9981";  // Enter Wi-Fi password

// Add your MQTT Broker IP address, example:

//const char* mqtt_server = "192.168.1.144";

const char* mqtt_server = "broker.mqtt-dashboard.com";

const char *mqtt_username = "alex9ufo";

const char *mqtt_password = "public";

const int mqtt_port = 1883;

WiFiClient espClient;

PubSubClient client(espClient);

char msg[50];

const char *topic1 = "alex9ufo/ESP32/LED_output";

const char *topic2 = "alex9ufo/ESP32/LED_status";

// LED Pin

#define BUILTIN_LED 2

String json = "";     //client.publish("alex9ufo/led/led_status",

char jsonChar1[20];

bool Send = false;  //true

//宣告任務Task1

TaskHandle_t Task1;

//===========================================================

//任務1副程式Task1_senddata

void Task1_senddata(void * pvParameters ) {

  //無窮迴圈

  for (;;) {

   

  if (client.connected()) {        

    if (Send) {

      // Convert JSON string to character array

      json.toCharArray(jsonChar1, json.length()+1);

      Serial.print("Publish message: ");

      Serial.println(json);

      // Publish JSON character array to MQTT topic

      client.publish(topic2,jsonChar1); //"alex9ufo/esp32/led_status";

    }

      Send = false;    

  }

  else

  {

    if (WiFi.status() != WL_CONNECTED)  {

      Serial.println("Reconnecting to WiFi...");

      WiFi.disconnect();

       WiFi.reconnect();

    }

  }

  //Task1休息，delay(X)不可省略

  delay(1000);

  }

}

//==========================================

void setup() {

  Serial.begin(115200);

  // default settings

  delay(500);

  setup_wifi();

  client.setServer(mqtt_server, mqtt_port);

  client.setCallback(callback);

  while (!client.connected()) {

    String client_id = "esp32-client-";

    client_id += String(WiFi.macAddress());

    Serial.printf("The client %s connects to the public MQTT broker\n", client_id.c_str());

    if (client.connect(client_id.c_str(), mqtt_username, mqtt_password)) {

        Serial.println("Public HiveMQ MQTT broker (broker.mqtt-dashboard.com) connected");

    } else {

        Serial.print("Failed with state ");

        Serial.print(client.state());

        delay(2000);

    }

  }

  // Publish and subscribe

  client.subscribe(topic1);

  pinMode(BUILTIN_LED, OUTPUT);

  //在核心0啟動任務1

  xTaskCreatePinnedToCore(

  Task1_senddata, /*任務實際對應的Function*/

    "Task1",        /*任務名稱*/

    10000,          /*堆疊空間*/

    NULL,           /*無輸入值*/

    0,              /*優先序0*/

    &Task1,         /*對應的任務變數位址*/

    0);             /*指定在核心0執行 */

}

//==========================================

void setup_wifi() {

  delay(10);

  // We start by connecting to a WiFi network

  Serial.println();

  Serial.print("Connecting to ");

  Serial.println(ssid);

  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {

    delay(500);

    Serial.print(".");

  }

  Serial.println("");

  Serial.println("ESP32 WiFi connected to ");

  Serial.println("IP address: ");

  Serial.println(WiFi.localIP());

}

//==========================================

void callback(char* topic, byte* message, unsigned int length) {

  Serial.print("Message arrived on topic: ");

  Serial.print(topic);

  Serial.print(". Message: ");

  String messageTemp;

 

  for (int i = 0; i < length; i++) {

    Serial.print((char)message[i]);

    messageTemp += (char)message[i];

  }

  Serial.println();

  // Feel free to add more if statements to control more GPIOs with MQTT

  // If a message is received on the topic esp32/output, you check if the message is either "on" or "off".

  // Changes the output state according to the message

  if (String(topic) == "alex9ufo/ESP32/LED_output")

  {

    Serial.print("Changing output to ");

    if(messageTemp == "on"){

      Serial.println("on");

      digitalWrite(BUILTIN_LED, HIGH);

      json ="LED ON";

      Send = true ;

    }

    else if(messageTemp == "off"){

      Serial.println("off");

      digitalWrite(BUILTIN_LED, LOW);

      json ="LED OFF";

      Send = true ;

    }

   

  }

}

//==========================================

void reconnect() {

  // Loop until we're reconnected

  while (!client.connected()) {

    Serial.print("Attempting MQTT connection...");

    // Attempt to connect

    if (client.connect("ESP32Client")) {

      Serial.println("connected");

      // Subscribe

      client.subscribe(topic1);

    } else {

      Serial.print("failed, rc=");

      Serial.print(client.state());

      Serial.println(" try again in 5 seconds");

      // Wait 5 seconds before retrying

      delay(5000);

    }

  }

}

//==========================================

void loop()

{

  if (!client.connected()) {

    reconnect();

    Serial.print(" client not connected  reconnect ");

    delay(200);

  }

  client.loop();

}

//=====================================================