WOKWI ESP32 DHT22 + ThinkSpeak +MQTT

 WOKWI ESP32  DHT22 + ThinkSpeak +MQTT 

WoKWI 程式

#include <WiFi.h>

#include "DHTesp.h"

#include "ThingSpeak.h"

#include <ArduinoMqttClient.h>

//WiFiClient wifiClient - creates a Wi-Fi client.

//MqttClient mqttClient(wifiClient) - connects the Wi-Fi client to the MQTT client.

//WiFi.begin(ssid, pass) - connects to local Wi-Fi network.

//mqttClient.connect(broker, port) - connects to broker (and port).

//mqttClient.poll() - keeps the connection alive, used in the loop().

//mqttClient.beginMessage(topic) - creates a new message to be published.

//mqttClient.print() - prints the content of message between the ().

//mqttClient.endMessage() - publishes the message to the broker.

//mqttClient.subscribe(topic) - subscribes to a topic.

//mqttClient.available() - checks if any messages are available from the topic.

//mqttClient.read() - reads the incoming messages.

const int DHT_PIN = 15;

const int LED_PIN = 13;

const char* WIFI_NAME = "Wokwi-GUEST";

const char* WIFI_PASSWORD = "";

const int myChannelNumber = 622462;

const char* myApiKey = "8U11H22OD8L4P9L718";

const char* server = "api.thingspeak.com";

unsigned long previousMillis = 0;

unsigned long interval = 10000;

DHTesp dhtSensor;

WiFiClient wifiClient;

MqttClient mqttClient(wifiClient);

//const char broker[] = "test.mosquitto.org";

const char broker[] = "broker.emqx.io";

int        port     = 1883;

const char *PubTopic1 = "alex9ufo/DHT22/Temp";

const char *PubTopic2 = "alex9ufo/DHT22/Humi";

const char *SubTopic1 = "alex9ufo/DHT22/Temp";

const char willTopic[] = "alex9ufo/Starting";

String json1 = "";

String json2 = "";

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

void onMqttMessage(int messageSize) {

  // we received a message, print out the topic and contents

  Serial.print("Received a message with topic '");

  Serial.print(mqttClient.messageTopic());

  String Topic= mqttClient.messageTopic();

  Serial.print("', duplicate = ");

  Serial.print(mqttClient.messageDup() ? "true" : "false");

  Serial.print(", QoS = ");

  Serial.print(mqttClient.messageQoS());

  Serial.print(", retained = ");

  Serial.print(mqttClient.messageRetain() ? "true" : "false");

  Serial.print("', length ");

  Serial.print(messageSize);

  Serial.println(" bytes:");

  String message="";

  // use the Stream interface to print the contents

  while (mqttClient.available()) {

    //Serial.print((char)mqttClient.read());

    message += (char)mqttClient.read();

  }

  Serial.println(message);

  message.trim();

  Topic.trim();

 

  Serial.println();

  Serial.println("-----------------------");

}

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

//副程式  setup wifi

void setup_wifi() {

  delay(10);

  // We start by connecting to a WiFi network

  Serial.println();

  Serial.print("Connecting to ");

  Serial.println(WIFI_NAME);     //print ssid

  WiFi.begin(WIFI_NAME, WIFI_PASSWORD);

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

    delay(500);

    Serial.print(".");

  }   //假設 wifi 未連接 show ………

  Serial.println("");

  Serial.println("WiFi connected");

  Serial.println("IP address: ");

  Serial.println(WiFi.localIP());

}  

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

void setup() {

  Serial.begin(115200);

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

  pinMode(LED_PIN, OUTPUT);

  digitalWrite(LED_PIN, HIGH);

  setup_wifi();

  Serial.println("You're connected to the network");

  Serial.println();

  //WiFi.mode(WIFI_STA);

  ThingSpeak.begin(wifiClient);

  String willPayload = "ESP32 Start working....!";

  bool willRetain = true;

  int willQos = 1;

  mqttClient.beginWill(willTopic, willPayload.length(), willRetain, willQos);

  mqttClient.print(willPayload);

  mqttClient.endWill();

  Serial.print("Attempting to connect to the MQTT broker: ");

  Serial.println(broker);

  if (!mqttClient.connect(broker, port)) {

    Serial.print("MQTT connection failed! Error code = ");

    Serial.println(mqttClient.connectError());

    while (1);

  }

  Serial.println("You're connected to the MQTT broker!");

  Serial.println();

  // set the message receive callback

  mqttClient.onMessage(onMqttMessage);

  Serial.print("Subscribing to topic: ");

  Serial.println(SubTopic1);

 

  // subscribe to a topic

  // the second parameter sets the QoS of the subscription,

  // the the library supports subscribing at QoS 0, 1, or 2

  int subscribeQos = 1;

  mqttClient.subscribe(SubTopic1, subscribeQos);

  Serial.println();

  delay(4);       // Optional delay. Some board do need more time after init to be ready, see Readme

}

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

void loop() {

  // call poll() regularly to allow the library to send MQTT keep alive which

  // avoids being disconnected by the broker

  mqttClient.poll();

  unsigned long currentMillis = millis();

  if (currentMillis - previousMillis >=interval) {

  int randNumber1 = random(1, 25);

  int randNumber2 = random(5, 9);

  TempAndHumidity  data = dhtSensor.getTempAndHumidity();

  ThingSpeak.setField(1,data.temperature+randNumber1);

  ThingSpeak.setField(2,data.humidity+randNumber2);

 

  //if (mqttClient.available()) {

    bool retained = false;

    int qos = 1;

    bool dup = false;

 

    json1=String(data.temperature+randNumber1, 2);

    mqttClient.beginMessage(PubTopic1,  json1.length(), retained, qos, dup);

    mqttClient.print(json1);

    mqttClient.endMessage();

    Serial.print(PubTopic1);

    Serial.println(json1);

    delay(1000);

    json2=String(data.humidity+randNumber2, 1);

    mqttClient.beginMessage(PubTopic2,  json2.length(), retained, qos, dup);

    mqttClient.print(json2);

    mqttClient.endMessage();

    Serial.print(PubTopic2);

    Serial.println(json2);

  //}

  if (data.temperature+randNumber1 > 35 || data.temperature+randNumber1 < 12 || data.humidity+randNumber2 > 70 || data.humidity+randNumber2 < 40) {

    digitalWrite(LED_PIN, LOW);

  }else{

    digitalWrite(LED_PIN, HIGH);

  }

 

  int x = ThingSpeak.writeFields(myChannelNumber,myApiKey);

 

  Serial.println("Temp: " + String(data.temperature+randNumber1, 2) + "°C");

  Serial.println("Humidity: " + String(data.humidity+randNumber2, 1) + "%");

 

  if(x == 200){

    Serial.println("Data pushed successfull");

  }else{

    Serial.println("Push error" + String(x));

  }

  Serial.println("---");

 

  previousMillis = currentMillis;

  }

  /* ... */

  if (!mqttClient.connected()) {

    Serial.println("MQTT connection lost");

    if (!mqttClient.connect(broker, port)) {

      Serial.print("MQTT reconnection error ");

      Serial.println(mqttClient.connectError());

    }

  }

}

Node-Red程式

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