alex9ufo 聰明人求知心切: ESP32 MQTT　＋node-red　　測試程式（實驗２

ESP32 MQTT＋node-red　測試程式（實驗２－１）

const char* mqtt_server = "broker.mqtt-dashboard.com";
const char *topic3 = "alex9ufo/esp32/led_status";
const char *topic1 = "alex9ufo/esp32/led";
const char *topic = "alex9ufo/esp32/Starting";

Installing the PubSubClient Library 安裝MQTT PubSubClient 程式庫

The PubSubClient library provides a client for doing simple publish/subscribe messaging with a server that supports MQTT (basically allows your ESP32 to talk with Node-RED).

Click here to download the PubSubClient library. You should have a .zip folder in your Downloads folder
Unzip the .zip folder and you should get pubsubclient-master folder
Rename your folder from ~~pubsubclient-master~~ to pubsubclient
Move the pubsubclient folder to your Arduino IDE installation libraries folder
Then, re-open your Arduino IDE

The library comes with a number of example sketches. See File >Examples > PubSubClient within the Arduino IDE software.

Important: PubSubClient is not fully compatible with the ESP32, but the example provided in this tutorial is working very reliably during our tests.

//====================================================
#include <WiFi.h>
#include <PubSubClient.h>

// Replace the next variables with your SSID/Password combination
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 = "broker.mqtt-dashboard.com";
const char* mqtt_server = "broker.mqtt-dashboard.com";
const char *topic3 = "alex9ufo/esp32/led_status";
const char *topic1 = "alex9ufo/esp32/led";
const char *topic = "alex9ufo/esp32/Starting";
const char *mqtt_username = "alex9ufo";
const char *mqtt_password = "public";
const int mqtt_port = 1883;


WiFiClient espClient;
PubSubClient client(espClient);
long lastMsg = 0;
char msg[50];
int value = 0;
char jsonChar1[50]; 

String json = "";
bool Flash = false;  //true
bool Timer = false;  //true
bool Send = false;  //true
int Count= 0;
bool ledState = false;

// LED Pin
const int ledPin = 2;  //Buildin LED
//====================================================
void setup() {
  Serial.begin(115200);
  // default settings
  setup_wifi();
  client.setServer(mqtt_server, 1883);
  client.setCallback(callback);
  pinMode(ledPin, OUTPUT);
  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);
    client.publish(topic,"ESP32 at work");
}
//====================================================
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("WiFi connected");
  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") {
    Serial.print("Changing output to ");
    if (messageTemp == "on" && !ledState) {
        digitalWrite(ledPin, HIGH);  // Turn on the LED
        ledState = true;  //ledState = ture HIGH
        Flash = false;
        Timer = false;
        json ="ON";
        Send = true ;
    }
    if (messageTemp == "off" && ledState) {
        digitalWrite(ledPin, LOW); // Turn off the LED
        ledState = false; //ledState = false LOW
        Flash = false;
        Timer = false;
        json ="OFF";
        Send = true ;

    }
    if (messageTemp == "flash" ) {
        digitalWrite(ledPin, LOW); // Turn off the LED
        Flash = true;
        Timer = false;
        json ="FLASH";
        Send = true ;        

    }
    if (messageTemp == "timer" ) {
        digitalWrite(ledPin, LOW); // Turn off the LED
        Flash = false;
        Timer = true;
        json ="TIMER";
        Send = true ;
        Count= 11;
    }

    if (messageTemp == "toggle" ) {
        digitalWrite(ledPin, !digitalRead(ledPin));   // Turn the LED toggle 
        if (digitalRead(ledPin)) 
            ledState = true;
        else
            ledState = false; 
        
        Flash = false;
        Timer = false;
        json ="TOGGLE";
        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("alex9ufo/esp32/led");
    } 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() {
  // 不需要 reconnect();
  //if (!client.connected()) {
  //  reconnect();
  //}

  client.loop();

    if (Flash){
        digitalWrite(ledPin, !digitalRead(ledPin));
        delay(500);
        if (digitalRead(ledPin)) 
            ledState = true;
        else
            ledState = false; 
    } //(Flash)
        
    if (Timer) {
        digitalWrite(ledPin, HIGH);
        delay(500);
        if (digitalRead(ledPin)) 
            ledState = true;
        else
            ledState = false; 

        Count=Count-1;
        if (Count == 0 ){
            Timer=false;
            digitalWrite(ledPin, LOW);
            ledState = false;
        }
    } //(Timer)

    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(topic3,jsonChar1);
        } 
        Send = false;    
    }



  long now = millis();
  if (now - lastMsg > 5000) {
    lastMsg = now;
 
  }
}
//====================================================

alex9ufo 聰明人求知心切

2023年8月17日星期四

ESP32 MQTT　＋node-red　　測試程式（實驗２－１）

Installing the PubSubClient Library 安裝MQTT PubSubClient 程式庫

沒有留言:

張貼留言

2024產專班作業2 (純模擬)

2023年8月17日 星期四

ESP32 MQTT ＋node-red 測試程式（實驗２－１）

Installing the PubSubClient Library 安裝MQTT PubSubClient 程式庫

沒有留言:

張貼留言

2024產專班 作業2 (純模擬)

2023年8月17日星期四

ESP32 MQTT　＋node-red　　測試程式（實驗２－１）

2024產專班作業2 (純模擬)