WOKWI MQTT (DHT22 & 16*2 LCD & LED)

 WOKWI  MQTT (DHT22 & 16*2 LCD & LED)

const char* mqtt_server = "broker.mqttgo.io";

const char Pubtopic1[]  = "alex9ufo/temp";

const char Pubtopic2[]  = "alex9ufo/hum";

const char Subtopic1[]  = "alex9ufo/command";

WOKWI程式

#include <WiFi.h>

#include <PubSubClient.h>

#include <LiquidCrystal_I2C.h>

#include "DHTesp.h"

const int DHT_PIN = 15;

const int LED = 2;

DHTesp dhtSensor;

#define I2C_ADDR    0x27

#define LCD_COLUMNS 20

#define LCD_LINES   4

LiquidCrystal_I2C lcd(I2C_ADDR, LCD_COLUMNS, LCD_LINES);

// Update these with values suitable for your network.

const char* ssid =  "Wokwi-GUEST";   // your network SSID (name)

const char* password = "";   // your network password

//const char* mqtt_server = "broker.mqttdashboard.com";// choose your mqtt server

const char* mqtt_server = "broker.mqttgo.io";

//const char* mqtt_server = "test.mosquitto.org";

const char Pubtopic1[]  = "alex9ufo/temp";

const char Pubtopic2[]  = "alex9ufo/hum";

const char Subtopic1[]  = "alex9ufo/command";

WiFiClient espClient;

PubSubClient client(espClient);

long lastMsg = 0;

char msg[50];

int value = 0;

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

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

{

  Serial.print("Command from MQTT broker is : [");

  Serial.print(topic);

  Serial.print("]");

  Serial.println();

  Serial.print(" publish data is:");

  lcd.clear();

  String message="";

  {

    for(int i=0;i<length;i++)

    {

      Serial.print((char)payload[i]);  

      message +=(char)payload[i];

      lcd.setCursor(0, 0);

      lcd.print("alex9ufo LCD"); // Start Print text to Line 1

      lcd.setCursor(i, 1);

      lcd.write((char)payload[i]);

    }

  }

 

  //Serial.println(message);

  message.trim();

  if (message == "on") {

      digitalWrite(LED, LOW);  // Turn on the LED

      Serial.print("LED = on ");

  }

  if (message == "off" ) {

      digitalWrite(LED, HIGH); // Turn off the LED

      Serial.print("LED = off ");

  }

  Serial.println();

} //end callback

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

void reconnect() {

  // Loop until we're reconnected

  while (!client.connected())

  {

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

    // Create a random client ID

    String clientId = "ESP32Client-";

    clientId += String(random(0xffff), HEX);

    // Attempt to connect

    //if you MQTT broker has clientID,username and password

    //please change following line to    if (client.connect(clientId,userName,passWord))

    if (client.connect(clientId.c_str()))

    {

      Serial.println("connected");

      //once connected to MQTT broker, subscribe command if any

      //client.subscribe("alex9ufo/Command");

      client.subscribe(Subtopic1);

    } else {

      Serial.print("failed, rc=");

      Serial.print(client.state());

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

      // Wait 6 seconds before retrying

      delay(6000);

    }

  }

} //end reconnect()

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

void setup_wifi() {

   delay(100);

  // We start by connecting to a WiFi network

    Serial.print("Connecting to ");

    Serial.println(ssid);

    WiFi.begin(ssid, password);

    while (WiFi.status() != WL_CONNECTED)

    {

      delay(500);

      Serial.print(".");

    }

  randomSeed(micros());

  Serial.println("");

  Serial.println("WiFi connected");

  Serial.println("IP address: ");

  Serial.println(WiFi.localIP());

}

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

void setup() {

  Serial.begin(115200);

 

  pinMode(LED, OUTPUT);     // Initialize the BUILTIN_LED pin as an output

  dhtSensor.setup(DHT_PIN, DHTesp::DHT22);

  setup_wifi();

  client.setServer(mqtt_server, 1883);

 

  // Init

  lcd.init();

  lcd.backlight();

  // Print something

  lcd.setCursor(3, 0);

  lcd.print("Welcome to");

  lcd.setCursor(2, 1);

  lcd.print("lcd display");

  lcd.setCursor(5, 2);

  lcd.print("Simulator");

  lcd.setCursor(7, 3);

  lcd.print("Enjoy!");

}

void loop() {

    if (!client.connected()) {

    reconnect();

  }

  client.setCallback(callback);

  client.loop();

  unsigned long now = millis();

  if (now - lastMsg > 5000) {

    lastMsg = now;

    TempAndHumidity  data = dhtSensor.getTempAndHumidity();

    String temp = String(data.temperature, 2);

    Serial.print("Temperature: ");

    Serial.println(temp);

    client.publish("alex9ufo/temp", temp.c_str());

   

    String hum = String(data.humidity, 1);

    Serial.print("Humidity: ");

    Serial.println(hum);

    client.publish("alex9ufo/hum", hum.c_str());

  }

}