alex9ufo 聰明人求知心切: 實驗 ESP32 MQTT – Publish and Subscribe Control Build LED

實驗 ESP32 MQTT – Publish and Subscribe Control Build LED
#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/LEDOUTPUT";
const char *topic2 = "alex9ufo/ESP32/LED_status";

// LED Pin
#define BUILTIN_LED 2
String json = "";     //client.publish("alex9ufo/led/led_status",
char jsonChar2[20];
bool Flash = false;  //true
bool Timer = false;  //true
bool Send = false;  //true
int Count= 0;
//==========================================
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);
}
//==========================================
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/LEDOUTPUT") {
    Serial.print("Changing output to ");
    if(messageTemp == "on"){
      Serial.println("on");
      digitalWrite(BUILTIN_LED, HIGH);
      Flash = false;
      Timer = false;
      json ="ON";
      Send = true ;
    }
    else if(messageTemp == "off"){
      Serial.println("off");
      digitalWrite(BUILTIN_LED, LOW);
      Flash = false;
      Timer = false;
      json ="OFF";
      Send = true ;
    }
    else if(messageTemp == "toggle"){
      digitalWrite(BUILTIN_LED, !digitalRead(BUILTIN_LED));   // Turn the LED toggle 
      bool val = digitalRead (BUILTIN_LED);
      Serial.println("toggle");
      Flash = false; 
      Timer = false;
      Send = true ;   
      json ="TOGGLE now=off "; 
      if (val) {
        json ="TOGGLE now=on ";
      }
  
    }
    else if(messageTemp == "flash"){
      digitalWrite(BUILTIN_LED, HIGH);   // Turn the LED off (Note that HIGH is the voltage level
      Serial.println("flash");
      Flash = true;
      Timer = false;
      json ="FLASH";
      Send = true ;  
    }
    else if(messageTemp == "timer"){
      digitalWrite(BUILTIN_LED, HIGH);   // Turn the LED off (Note that HIGH is the voltage level
      Serial.println("timer");
      Flash = false;
      Timer = true;
      Count= 10;
      json ="TIMER";
      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();
  }
  client.loop();
  //----------------------------------
  if (Flash)
  {
    digitalWrite(BUILTIN_LED, !digitalRead(BUILTIN_LED));
    delay(500);
  }
  if (Timer) 
  {
    digitalWrite(BUILTIN_LED, HIGH);
    delay(500);
    Count=Count-1;
    if (Count == 0 ){
       Timer=false;
       digitalWrite(BUILTIN_LED, LOW);
    }
  }
  if (Send) {
    // Convert JSON string to character array

    json.toCharArray(jsonChar2, json.length()+1);
    if  (client.connected()) {
         Serial.print("Publish message: ");
         Serial.println(json);
         // Publish JSON character array to MQTT topic
         client.publish(topic2,jsonChar2);
    } 
    Send = false;    
  }
  //----------------------------------

}
alex9ufo 聰明人求知心切

2023年7月13日星期四

實驗 ESP32 MQTT – Publish and Subscribe Control Build LED

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張貼留言

2024_09 作業3 以Node-Red 為主

2023年7月13日 星期四

實驗 ESP32 MQTT – Publish and Subscribe Control Build LED

沒有留言:

張貼留言

2024_09 作業3 以Node-Red 為主

2023年7月13日星期四
