alex9ufo 聰明人求知心切: ESP32 MQTT – Publish and Subscribe with Arduino IDE

ESP32 MQTT – Publish and Subscribe with Arduino IDE

參考來源 https://randomnerdtutorials.com/esp32-mqtt-publish-subscribe-arduino-ide/

Installing the PubSubClient Library

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.

/*********
  Rui Santos
  Complete project details at https://randomnerdtutorials.com  
*********/
#include <WiFiManager.h>         // https://github.com/tzapu/WiFiManager
//#include <WiFiClientSecure.h>

#include <PubSubClient.h>
// REQUIRES the following Arduino libraries:
// - DHT Sensor Library: https://github.com/adafruit/DHT-sensor-library
// - Adafruit Unified Sensor Lib: https://github.com/adafruit/Adafruit_Sensor

#include <Adafruit_Sensor.h>
#include <DHT.h>
#include <DHT_U.h>

#define DHTPIN 27     // Digital pin connected to the DHT sensor 
// Feather HUZZAH ESP8266 note: use pins 3, 4, 5, 12, 13 or 14 --
// Pin 15 can work but DHT must be disconnected during program upload.

// Uncomment the type of sensor in use:
//#define DHTTYPE    DHT11     // DHT 11
#define DHTTYPE    DHT22     // DHT 22 (AM2302)
//#define DHTTYPE    DHT21     // DHT 21 (AM2301)
DHT_Unified dht(DHTPIN, DHTTYPE);
uint32_t delayMS;

// Add your MQTT Broker IP address, example:
//const char* mqtt_server = "192.168.1.144";
const char* mqtt_server = "broker.mqtt-dashboard.com";

WiFiClient espClient;
PubSubClient client(espClient);
long lastMsg = 0;
char msg[50];
int value = 0;
String json = "";    
char jsonChar1[100];  //client.publish("alex9ufo/Esp32/temperature"
char jsonChar2[100];  //client.publish("alex9ufo/Esp32/humidity"

// LED Pin
const int ledPin = 2;   //Build in LED
//======================================================
void autoconnect() {
  // WiFi.mode(WIFI_STA); // explicitly set mode, esp defaults to STA+AP
  // it is a good practice to make sure your code sets wifi mode how you want it.

  // put your setup code here, to run once:
  delay(1000);
  // We start by connecting to a WiFi network
  Serial.println();
  Serial.println();
  Serial.print("Connecting to "); 
  //===================================================  
  // WiFiManager
  // Local intialization. Once its business is done, there is no need to keep it around
  WiFiManager wifiManager;
  
  // Uncomment and run it once, if you want to erase all the stored information
  //wifiManager.resetSettings();
  
  // set custom ip for portal
  //wifiManager.setAPConfig(IPAddress(10,0,1,1), IPAddress(10,0,1,1), IPAddress(255,255,255,0));

  // fetches ssid and pass from eeprom and tries to connect
  // if it does not connect it starts an access point with the specified name
  // here  "AutoConnectAP"
  // and goes into a blocking loop awaiting configuration
  //=================================================
  Serial.println("Configuring your Mobile WiFi to esp32ap...");
  Serial.println("Configuring another WiFi SSID,PWD...");
  //===================================================  
  wifiManager.autoConnect("AutoConnectAP");
  // or use this for auto generated name ESP + ChipID
  //wifiManager.autoConnect();
  
  // if you get here you have connected to the WiFi
  Serial.println("Connected.");

  Serial.println("Configuring ESP32...");
  
}

//================================================
void setup() {
  Serial.begin(115200);
  //================================================
  autoconnect();
   //================================================================
  //espClient.setInsecure();//ESP32核心 1.0.6以上  
  // 會遇到「Connection Failed」的問題，主要是因為ESP32的1.0.6的核心會強迫使用SSL認證，
  //此時可以先透過在Setup()內加上「client.setInsecure();」語法來解決
  //================================================================
  client.setServer(mqtt_server, 1883);
  client.setCallback(callback);

  pinMode(ledPin, OUTPUT);
  // default settings
  dht.begin();
  Serial.println(F("DHTxx Unified Sensor Example"));
  // Print temperature sensor details.
  sensor_t sensor;
  dht.temperature().getSensor(&sensor);
  Serial.println(F("------------------------------------"));
  Serial.println(F("Temperature Sensor"));
  Serial.print  (F("Sensor Type: ")); Serial.println(sensor.name);
  Serial.print  (F("Driver Ver:  ")); Serial.println(sensor.version);
  Serial.print  (F("Unique ID:   ")); Serial.println(sensor.sensor_id);
  Serial.print  (F("Max Value:   ")); Serial.print(sensor.max_value); Serial.println(F("°C"));
  Serial.print  (F("Min Value:   ")); Serial.print(sensor.min_value); Serial.println(F("°C"));
  Serial.print  (F("Resolution:  ")); Serial.print(sensor.resolution); Serial.println(F("°C"));
  Serial.println(F("------------------------------------"));
  // Print humidity sensor details.
  dht.humidity().getSensor(&sensor);
  Serial.println(F("Humidity Sensor"));
  Serial.print  (F("Sensor Type: ")); Serial.println(sensor.name);
  Serial.print  (F("Driver Ver:  ")); Serial.println(sensor.version);
  Serial.print  (F("Unique ID:   ")); Serial.println(sensor.sensor_id);
  Serial.print  (F("Max Value:   ")); Serial.print(sensor.max_value); Serial.println(F("%"));
  Serial.print  (F("Min Value:   ")); Serial.print(sensor.min_value); Serial.println(F("%"));
  Serial.print  (F("Resolution:  ")); Serial.print(sensor.resolution); Serial.println(F("%"));
  Serial.println(F("------------------------------------"));
  // Set delay between sensor readings based on sensor details.
  delayMS = sensor.min_delay / 1000;
  pinMode(ledPin, OUTPUT);
}

//================================================
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/output") {
    Serial.print("Changing output to ");
    if(messageTemp == "on"){
      Serial.println("on");
      digitalWrite(ledPin, LOW);
    }
    else if(messageTemp == "off"){
      Serial.println("off");
      digitalWrite(ledPin, HIGH);
    }
  }
}
//================================================
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/output");
    } 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();

  long now = millis();
  if (now - lastMsg > 15000) {
    lastMsg = now;
    dht.begin();
    // Delay between measurements.
    delay(delayMS);
    // Get temperature event and print its value.
    sensors_event_t event;
    // Temperature in Celsius
    dht.temperature().getEvent(&event);
    if (isnan(event.temperature)) {
      Serial.println(F("Error reading temperature!"));
    }
    else {
      Serial.print(F("Temperature: "));
      Serial.print(event.temperature);
      Serial.println(F("°C"));
          
      String json1 =String(event.temperature);
      // Convert JSON string to character array
      json1.toCharArray(jsonChar1, json1.length()+1);
      client.publish("alex9ufo/esp32/temperature", jsonChar1);
    }
 
      // Get humidity event and print its value.
    dht.humidity().getEvent(&event);
    if (isnan(event.relative_humidity)) {
      Serial.println(F("Error reading humidity!"));
    }
    else {
      Serial.print(F("Humidity: "));
      Serial.print(event.relative_humidity);
      Serial.println(F("%"));

      String json2=String(event.relative_humidity);  
      // Convert the value to a char array
      json2.toCharArray(jsonChar2, json2.length()+1);
      client.publish("alex9ufo/esp32/humidity", jsonChar2);
    }  
  }
}

alex9ufo 聰明人求知心切

2023年7月8日星期六

ESP32 MQTT – Publish and Subscribe with Arduino IDE

Installing the PubSubClient Library

沒有留言:

張貼留言

Messaging API作為替代方案

2023年7月8日 星期六

ESP32 MQTT – Publish and Subscribe with Arduino IDE

Installing the PubSubClient Library

沒有留言:

張貼留言

Messaging API作為替代方案

2023年7月8日星期六