ESP32 MQTT – Publish DS18B20 Temperature Readings

 ESP32 MQTT – Publish DS18B20 Temperature Readings 

WOKWI程式

#include <WiFi.h>

#include "Adafruit_MQTT.h"

#include "Adafruit_MQTT_Client.h"

#include <OneWire.h>

#include <DallasTemperature.h>

#define WLAN_SSID "Wokwi-GUEST"

#define WLAN_PASS ""

/************************* Adafruit.io Setup ***************************/

#define AIO_SERVER      "broker.hivemq.com"

#define AIO_SERVERPORT  1883                   // use 8883 for SSL

#define AIO_USERNAME    ""

#define AIO_KEY         ""

#define AIO_FEED_1      "alex9ufo/esp32/ds18b20/temperature"

// Raspberry Pi Mosquitto MQTT Broker

//#define MQTT_HOST IPAddress(192, 168, 1, XXX)

// For a cloud MQTT broker, type the domain name

// Create an ESP8266 WiFiClient class to connect to the MQTT server.

WiFiClient client;

// Setup the MQTT client class by passing in the WiFi client and MQTT server and login details.

Adafruit_MQTT_Client mqtt(&client, AIO_SERVER, AIO_SERVERPORT, AIO_USERNAME, AIO_USERNAME, AIO_KEY);

/****************************** Feeds ***************************************/

// Setup feeds 'temp' and 'hmdt' for publishing.

Adafruit_MQTT_Publish tempPub = Adafruit_MQTT_Publish(&mqtt, AIO_USERNAME AIO_FEED_1);

// Setup a feed called 'onoff' for subscribing to changes to the ON/OFF button

// GPIO where the DS18B20 is connected to

const int oneWireBus = 4;          

// Setup a oneWire instance to communicate with any OneWire devices

OneWire oneWire(oneWireBus);

// Pass our oneWire reference to Dallas Temperature sensor

DallasTemperature sensors(&oneWire);

// Temperature value

float temp;

unsigned long lastMsg = 0;

// Function to connect and reconnect as necessary to the MQTT server.

// Should be called in the loop function and it will take care if connecting.

void MQTT_connect() {

  int8_t ret;

  // Stop if already connected.

  if (mqtt.connected()) {

    return;

  }

  Serial.print("Connecting to MQTT... ");

  uint8_t retries = 3;

  while ((ret = mqtt.connect()) != 0) { // connect will return 0 for connected

    Serial.println(mqtt.connectErrorString(ret));

    Serial.println("Retrying MQTT connection in 10 seconds...");

    mqtt.disconnect();

    delay(10000);  // wait 10 seconds

    retries--;

    if (retries == 0) {

      // basically die and wait for WDT to reset me

      while (1);

    }

  }

  Serial.println("MQTT Connected!");

}

void setup() {

  // Start the DS18B20 sensor

  sensors.begin();

 

  Serial.begin(115200);

  Serial.println();

  Serial.println();

  // Connect to WiFi access point.

  Serial.print("Connecting to ");

  Serial.println(WLAN_SSID);

  WiFi.begin(WLAN_SSID, WLAN_PASS);

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

    delay(500);

    Serial.print(".");

  }

  Serial.println(); Serial.println("WiFi connected");

  Serial.println("IP address: "); Serial.println(WiFi.localIP());

}

void loop() {

  // Ensure the connection to the MQTT server is alive (this will make the first

  // connection and automatically reconnect when disconnected).  See the MQTT_connect

  // function definition further below.

  MQTT_connect();

  // this is our 'wait for incoming subscription packets and callback em' busy subloop

  // try to spend your time here:

  mqtt.processPackets(10000);

 

  // ping the server to keep the mqtt connection alive

  // NOT required if you are publishing once every KEEPALIVE seconds

 

  if(! mqtt.ping()) {

    mqtt.disconnect();

  }

 

  // Publish feeds

  unsigned long now = millis();

  if (now - lastMsg > 10000) {

    lastMsg = now;

    // New temperature readings

    sensors.requestTemperatures();

    // Temperature in Celsius degrees

    temp = sensors.getTempCByIndex(0);

    // Temperature in Fahrenheit degrees

    //temp = sensors.getTempFByIndex(0);

    Serial.println("Temperature: " +String(temp) + "°C");

    Serial.println("---");

    char strTemperature[20];

    sprintf(strTemperature, "%.1f", temp);

    tempPub.publish(strTemperature);

  }

}

Node-Red程式

[ { "id": "9a55977d9dd88494", "type": "mqtt in", "z": "72c4df790a4c757f", "name": "", "topic": "alex9ufo/esp32/ds18b20/temperature", "qos": "2", "datatype": "auto-detect", "broker": "2380dcc0d36d2c6a", "nl": false, "rap": true, "rh": 0, "inputs": 0, "x": 610, "y": 240, "wires": [ [ "ea3b6b36bf2cac5b" ] ] }, { "id": "ea3b6b36bf2cac5b", "type": "ui_gauge", "z": "72c4df790a4c757f", "name": "", "group": "4f4d1221d5fcd2d2", "order": 0, "width": 0, "height": 0, "gtype": "gage", "title": "gauge", "label": "°C", "format": "{{value}}", "min": "-55", "max": "125", "colors": [ "#00b500", "#e6e600", "#ca3838" ], "seg1": "25", "seg2": "50", "className": "", "x": 870, "y": 240, "wires": [] }, { "id": "2380dcc0d36d2c6a", "type": "mqtt-broker", "name": "", "broker": "broker.hivemq.com", "port": "1883", "clientid": "", "autoConnect": true, "usetls": false, "protocolVersion": "4", "keepalive": "60", "cleansession": true, "birthTopic": "", "birthQos": "0", "birthPayload": "", "birthMsg": {}, "closeTopic": "", "closeQos": "0", "closePayload": "", "closeMsg": {}, "willTopic": "", "willQos": "0", "willPayload": "", "willMsg": {}, "userProps": "", "sessionExpiry": "" }, { "id": "4f4d1221d5fcd2d2", "type": "ui_group", "name": "溫度", "tab": "096dc3f20d4aa28b", "order": 1, "disp": true, "width": "6", "collapse": false, "className": "" }, { "id": "096dc3f20d4aa28b", "type": "ui_tab", "name": "MQTT DS18B20", "icon": "dashboard", "order": 128, "disabled": false, "hidden": false } ]

MIT Inventor / WOKWI 4 LED Control / MQTT

MIT Inventor / WOKWI 4 LED Control / MQTT

#include <WiFi.h>

#include <PubSubClient.h>

//Relays for switching appliances

#define Relay1            15     //D15 LED-Orangs = Water-1

#define Relay2            2     //D2   LED-Blue  = Water-2

#define Relay3            19    //D19  LED-Blue   = Motor

#define Relay4            23    //D23  LED-RED    = Fan

//Nenu For Control

int menu;

//Changs to:

#define sub1 "alex9ufo/SWcnt1"

#define sub2 "alex9ufo/SWcnt2"

#define sub3 "alex9ufo/SWcnt3"

#define sub4 "alex9ufo/SWcnt4"

const char pubTopic[] = "alex9ufo/lights";

// 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.hivemq.com";

const char* username = "";

const char* pass = "";

WiFiClient espClient;

PubSubClient client(espClient);

unsigned long lastMsg = 0;

#define MSG_BUFFER_SIZE  (50)

char msg[MSG_BUFFER_SIZE];

int value = 0;

String onoffMsg="";

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

void setup_wifi() {

  delay(10);

  // We start by connecting to a WiFi network

  Serial.println();

  Serial.print("Connecting to ");

  Serial.println(ssid);

  WiFi.mode(WIFI_STA);

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

  Serial.print("Message arrived [");

  Serial.print(topic);

  Serial.print("] ");

  String messageTemp;

  for(int i=0; i<length; i+=1) {

    messageTemp += (char)payload[i];

  }

  messageTemp.trim();

  Serial.println(messageTemp);

 

  if (String(topic)=="alex9ufo/SWcnt1") {

      if(messageTemp=="ON"){

        Serial.println("Led1 ON");

        digitalWrite(Relay1,HIGH);

        onoffMsg="11";

      }  

      if(messageTemp=="OFF"){

        Serial.println("Led1 OFF");

        digitalWrite(Relay1,LOW);

        onoffMsg="10";

      }

  }

  if (String(topic)=="alex9ufo/SWcnt2") {

      if(messageTemp=="ON"){

        Serial.println("Led2 ON");

        digitalWrite(Relay2,HIGH);

        onoffMsg="21";

      }  

      if(messageTemp=="OFF"){

        Serial.println("Led2 OFF");

        digitalWrite(Relay2,LOW);

        onoffMsg="20";

      }

  }

  if (String(topic)=="alex9ufo/SWcnt3") {

      if(messageTemp=="ON"){

        Serial.println("Led3 ON");

        digitalWrite(Relay3,HIGH);

        onoffMsg="31";

      }  

      if(messageTemp=="OFF"){

        Serial.println("Led3 OFF");

        digitalWrite(Relay3,LOW);

        onoffMsg="30";          

      }

  }

  if (String(topic)=="alex9ufo/SWcnt4") {

      if(messageTemp=="ON"){

        Serial.println("Led4 ON");

        digitalWrite(Relay4,HIGH);

        onoffMsg="41";

      }  

      if(messageTemp=="OFF"){

        Serial.println("Led4 OFF");

        digitalWrite(Relay4,LOW);

        onoffMsg="40";

      }

  }

}

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

void reconnect() {

  while (!client.connected()) {

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

    String clientId = "ESP32Client-";

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

    // Attempt to connect

    if (client.connect(clientId.c_str(), username, pass) ) {

      Serial.println("connected");

      client.subscribe(sub1);

      client.subscribe(sub2);

      client.subscribe(sub3);

      client.subscribe(sub4);

    } else {

      Serial.print("failed, rc=");

      Serial.print(client.state());

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

      // Wait 5 seconds before retrying

      delay(5000);

    }

  }

}

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

void setup() {

  pinMode(Relay1, OUTPUT);

  pinMode(Relay2, OUTPUT);

  pinMode(Relay3, OUTPUT);

  pinMode(Relay4, OUTPUT);

  Serial.begin(115200);

  setup_wifi();

  client.setServer(mqtt_server, 1883);

  client.setCallback(callback);

  client.subscribe(sub1);

  client.subscribe(sub2);

  client.subscribe(sub3);

  client.subscribe(sub4);

}

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

void loop() {

  if (!client.connected()) {

    reconnect();

  }

  client.loop();

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

  if (onoffMsg=="10") {

      String msgStr = "10";

      byte arrSize = msgStr.length() + 1;

      char msg[arrSize];

      Serial.print("PUBLISH DATA: LED");

      Serial.println(msgStr);

      msgStr.toCharArray(msg, arrSize);

      client.publish(pubTopic, msg);

      onoffMsg= "";

      delay(50);

  }

  if (onoffMsg=="11") {

      String msgStr = "11";

      byte arrSize = msgStr.length() + 1;

      char msg[arrSize];

      Serial.print("PUBLISH DATA: LED");

      Serial.println(msgStr);

      msgStr.toCharArray(msg, arrSize);

      client.publish(pubTopic, msg);

      onoffMsg= "";

      delay(50);

  }

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

 if (onoffMsg=="20") {

      String msgStr = "20";

      byte arrSize = msgStr.length() + 1;

      char msg[arrSize];

      Serial.print("PUBLISH DATA: LED");

      Serial.println(msgStr);

      msgStr.toCharArray(msg, arrSize);

      client.publish(pubTopic, msg);

      onoffMsg= "";

      delay(50);

  }

  if (onoffMsg=="21") {

      String msgStr = "21";

      byte arrSize = msgStr.length() + 1;

      char msg[arrSize];

      Serial.print("PUBLISH DATA: LED");

      Serial.println(msgStr);

      msgStr.toCharArray(msg, arrSize);

      client.publish(pubTopic, msg);

      onoffMsg= "";

      delay(50);

  }

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

 if (onoffMsg=="30") {

      String msgStr = "30";

      byte arrSize = msgStr.length() + 1;

      char msg[arrSize];

      Serial.print("PUBLISH DATA: LED");

      Serial.println(msgStr);

      msgStr.toCharArray(msg, arrSize);

      client.publish(pubTopic, msg);

      onoffMsg= "";

      delay(50);

  }

  if (onoffMsg=="31") {

      String msgStr = "31";

      byte arrSize = msgStr.length() + 1;

      char msg[arrSize];

      Serial.print("PUBLISH DATA: LED");

      Serial.println(msgStr);

      msgStr.toCharArray(msg, arrSize);

      client.publish(pubTopic, msg);

      onoffMsg= "";

      delay(50);

  }

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

 if (onoffMsg=="40") {

      String msgStr = "40";

      byte arrSize = msgStr.length() + 1;

      char msg[arrSize];

      Serial.print("PUBLISH DATA: LED");

      Serial.println(msgStr);

      msgStr.toCharArray(msg, arrSize);

      client.publish(pubTopic, msg);

      onoffMsg= "";

      delay(50);

  }

  if (onoffMsg=="41") {

      String msgStr = "41";

      byte arrSize = msgStr.length() + 1;

      char msg[arrSize];

      Serial.print("PUBLISH DATA: LED");

      Serial.println(msgStr);

      msgStr.toCharArray(msg, arrSize);

      client.publish(pubTopic, msg);

      onoffMsg= "";

      delay(50);

  }

}

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

LED TEMPERATURE HUMIDITY APK Ver2.0 (ESP32. MQTT. Broker. Publish. Subscribe .MIT APP Inventor)

 LED TEMPERATURE HUMIDITY APK Ver2.0  (ESP32. MQTT. Broker. Publish. Subscribe .MIT APP Inventor)

參考來源 https://github.com/HighVoltages/Mqtt-in-Android-app---mit-app-inventor

MIT INVENTOR 程式

https://drive.google.com/file/d/1y1DJz7S6jgSd-jSFo_LUMlmXKUTHnkvP/view?usp=sharing

WOKWI程式

#include <WiFi.h>

#include <PubSubClient.h>

#include <ArduinoJson.h>

#include <DHTesp.h>

//

const int DHTPIN = 15;

const int LED = 13;

DHTesp dhtSensor;

uint32_t delayMS;

const char* ssid = "Wokwi-GUEST";

const char* password = "";

const char *mqtt_broker = "broker.hivemq.com";

const int mqtt_port = 1883;

//MQTT Credentials

const char* topic = "alex9ufo/Tempdata"; //publish topic

//parameters for using non-blocking delay

unsigned long previousMillis = 0;

const long interval = 5000;

String msgStr = "";      // MQTT message buffer

float temp, hum;

//setting up wifi and mqtt client

WiFiClient espClient;

PubSubClient client(espClient);

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

void setup_wifi() {

  delay(10);

  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 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 (client.connect(clientId.c_str())) {

      Serial.println("Connected");

      // Once connected, publish an announcement...

      //client.publish("alex9ufo/esp32", "iotfrontier");

      // ... and resubscribe

      client.subscribe("alex9ufo/lights");

    } else {

      Serial.print("failed, rc=");

      Serial.print(client.state());

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

      // Wait 5 seconds before retrying

      delay(5000);

    }

  }

}

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

//subscribe call back

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

  Serial.print("Message arrived in topic: ");

  Serial.println(topic);

  Serial.print("Message:");

  String data = "";

  for (int i = 0; i < length; i++) {

    Serial.print((char)payload[i]);

    data += (char)payload[i];

  }

  Serial.println();

  Serial.print("Message size :");

  Serial.println(length);

  Serial.println();

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

  Serial.println(data);

  if(data=="ON"){

    Serial.println("LED =on");

    digitalWrite(LED,LOW );

  }

  else{

    Serial.println("LED =off");

    digitalWrite(LED,HIGH );

  }

}

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

void setup() {

  Serial.begin(115200);

  // Initialize device.

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

  pinMode(LED, OUTPUT);

  digitalWrite(LED, LOW);

  setup_wifi();

  client.setServer(mqtt_broker , 1883); //setting MQTT server

  client.setCallback(callback); //defining function which will be called when message is recieved.

}

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

void loop() {

  if (!client.connected()) { //if client is not connected

    reconnect(); //try to reconnect

  }

  client.loop();

  unsigned long currentMillis = millis(); //read current time

  if (currentMillis - previousMillis >= interval) { //if current time - last time > 5 sec

    previousMillis = currentMillis;

    TempAndHumidity  data = dhtSensor.getTempAndHumidity();

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

    Serial.print("Temperature: ");

    Serial.println(temp);

    client.publish("alex9ufo/esp32/temperature", temp.c_str());

   

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

    Serial.print("Humidity: ");

    Serial.println(hum);

    msgStr = String(temp) +","+String(hum);

    byte arrSize = msgStr.length() + 1;

    char msg[arrSize];

    Serial.print("PUBLISH DATA:");

    Serial.println(msgStr);

    msgStr.toCharArray(msg, arrSize);

    client.publish(topic, msg);

    msgStr = "";

    delay(50);

  }

}

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