ESP8266 and Node-RED with MQTT (Publish and Subscribe)
/*****
All the resources for this project:
http://randomnerdtutorials.com/
*****/
#include <ESP8266WiFi.h>
#include <PubSubClient.h>
#include "DHT.h"
// Uncomment one of the lines bellow for whatever DHT sensor type you're using!
#define DHTTYPE DHT11 // DHT 11
//#define DHTTYPE DHT21 // DHT 21 (AM2301)
//#define DHTTYPE DHT22 // DHT 22 (AM2302), AM2321
// Change the credentials below, so your ESP8266 connects to your router
const char* ssid = "PTS-2F";
const char* password = "";
// Change the variable to your Raspberry Pi IP address, so it connects to your MQTT broker
const char* mqtt_server = "iot.eclipse.org";
// Initializes the espClient. You should change the espClient name if you have multiple ESPs running in your home automation system
WiFiClient espClient;
PubSubClient client(espClient);
// DHT Sensor - GPIO 5 = D1 on ESP-12E NodeMCU board
const int DHTPin = 5;
// Lamp - LED - GPIO 4 = D2 on ESP-12E NodeMCU board
const int lamp = 4;
// Initialize DHT sensor.
DHT dht(DHTPin, DHTTYPE);
// Timers auxiliar variables
long now = millis();
long lastMeasure = 0;
// Don't change the function below. This functions connects your ESP8266 to your router
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.print("WiFi connected - ESP IP address: ");
Serial.println(WiFi.localIP());
}
// This functions is executed when some device publishes a message to a topic that your ESP8266 is subscribed to
// Change the function below to add logic to your program, so when a device publishes a message to a topic that
// your ESP8266 is subscribed you can actually do something
void callback(String 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 room/lamp, you check if the message is either on or off. Turns the lamp GPIO according to the message
if(topic=="alex9ufoRoom/lamp"){
Serial.print("Changing Room lamp to ");
if(messageTemp == "on"){
digitalWrite(lamp, HIGH);
Serial.print("On");
}
else if(messageTemp == "off"){
digitalWrite(lamp, LOW);
Serial.print("Off");
}
}
Serial.println();
}
// This functions reconnects your ESP8266 to your MQTT broker
// Change the function below if you want to subscribe to more topics with your ESP8266
void reconnect() {
// Loop until we're reconnected
while (!client.connected()) {
Serial.print("Attempting MQTT connection...");
// Attempt to connect
/*
YOU MIGHT NEED TO CHANGE THIS LINE, IF YOU'RE HAVING PROBLEMS WITH MQTT MULTIPLE CONNECTIONS
To change the ESP device ID, you will have to give a new name to the ESP8266.
Here's how it looks:
if (client.connect("ESP8266Client")) {
You can do it like this:
if (client.connect("ESP1_Office")) {
Then, for the other ESP:
if (client.connect("ESP2_Garage")) {
That should solve your MQTT multiple connections problem
*/
if (client.connect("ESP8266Client")) {
Serial.println("connected");
// Subscribe or resubscribe to a topic
// You can subscribe to more topics (to control more LEDs in this example)
client.subscribe("alex9ufoRoom/lamp");
} else {
Serial.print("failed, rc=");
Serial.print(client.state());
Serial.println(" try again in 5 seconds");
// Wait 5 seconds before retrying
delay(5000);
}
}
}
// The setup function sets your ESP GPIOs to Outputs, starts the serial communication at a baud rate of 115200
// Sets your mqtt broker and sets the callback function
// The callback function is what receives messages and actually controls the LEDs
void setup() {
pinMode(lamp, OUTPUT);
dht.begin();
Serial.begin(115200);
setup_wifi();
client.setServer(mqtt_server, 1883);
client.setCallback(callback);
}
// For this project, you don't need to change anything in the loop function. Basically it ensures that you ESP is connected to your broker
void loop() {
if (!client.connected()) {
reconnect();
}
if(!client.loop())
client.connect("ESP8266Client");
now = millis();
// Publishes new temperature and humidity every 30 seconds
if (now - lastMeasure > 30000) {
lastMeasure = now;
// Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor)
float h = dht.readHumidity();
// Read temperature as Celsius (the default)
float t = dht.readTemperature();
// Read temperature as Fahrenheit (isFahrenheit = true)
float f = dht.readTemperature(true);
// Check if any reads failed and exit early (to try again).
if (isnan(h) || isnan(t) || isnan(f)) {
Serial.println("Failed to read from DHT sensor!");
return;
}
// Computes temperature values in Celsius
float hic = dht.computeHeatIndex(t, h, false);
static char temperatureTemp[7];
dtostrf(hic, 6, 2, temperatureTemp);
// Uncomment to compute temperature values in Fahrenheit
// float hif = dht.computeHeatIndex(f, h);
// static char temperatureTemp[7];
// dtostrf(hic, 6, 2, temperatureTemp);
static char humidityTemp[7];
dtostrf(h, 6, 2, humidityTemp);
// Publishes Temperature and Humidity values
client.publish("alex9ufoRoom/temp", temperatureTemp);
client.publish("alex9ufoRoom/humi", humidityTemp);
Serial.print("alex9ufoRoom/temp : ");
Serial.print(temperatureTemp);
Serial.print("%C \t alex9ufoRoom/humi : ");
Serial.print(humidityTemp);
Serial.println(" % ");
Serial.print("Humidity: ");
Serial.print(h);
Serial.print(" %\t Temperature: ");
Serial.print(t);
Serial.print(" *C ");
Serial.print(f);
Serial.print(" *F\t Heat index: ");
Serial.print(hic);
Serial.println(" *C ");
// Serial.print(hif);
// Serial.println(" *F");
}
}
沒有留言:
張貼留言