Home Automation Using MQTT and ESP8266
Nowadays, Home automation is the trending and the emerging era of IoT (Internet of Things). Everyone tries to automate home in some manner then that can be remote controlled or manual. And which makes life easier for them.
There are man techniques to control home appliances remotely.
In this article, we will see how to make home automation using MQTT protocol and esp8266. There are many boards, many devices which come ready in the market like sonoff. But I have made my own (lot more modification is pending) hardware. Let’s see one by one and proceed further.
What is MQTT?
MQTT stands for MQ Telemetry Transport. It is a publish/subscribe,
extremely simple and lightweight messaging protocol, designed for constrained devices and low-bandwidth, high-latency or unreliable networks. The design principles are to minimise network bandwidth and device resource requirements whilst also attempting to ensure reliability and some degree of assurance of delivery. These principles also turn out to make the protocol ideal of the emerging “machine-to-machine” (M2M) or “Internet of Things” world of connected devices, and for mobile applications where bandwidth and battery power are at a premium.
Schematic and Board Layout
Actual board
Code :
#include <ESP8266WiFi.h>
#include "Adafruit_MQTT.h"
#include "Adafruit_MQTT_Client.h"
// the on off button feed turns this LIGHT_PIN on/off
#define LIGHT_PIN1 5
#define LIGHT_PIN2 12
#define LIGHT_PIN3 4
#define LIGHT_PIN4 13
/************************* WiFi Access Point *********************************/
#define WLAN_SSID "hidden"
#define WLAN_PASS "qwerty12345"
/************************* Adafruit.io Setup *********************************/
#define AIO_SERVER "io.adafruit.com"
#define AIO_SERVERPORT 1883 // use 8883 for SSL
#define AIO_USERNAME "iotdev"
#define AIO_KEY "7cfc053140584a90af4cb13a769c9aed"
/************ Global State (you don't need to change this!) ******************/
// Create an ESP8266 WiFiClient class to connect to the MQTT server.
WiFiClient client;
// or... use WiFiFlientSecure for SSL
//WiFiClientSecure 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 ***************************************/
// Notice MQTT paths for AIO follow the form: <username>/feeds/<feedname>
Adafruit_MQTT_Subscribe light1 = Adafruit_MQTT_Subscribe(&mqtt, AIO_USERNAME "/feeds/light1");
Adafruit_MQTT_Subscribe light2 = Adafruit_MQTT_Subscribe(&mqtt, AIO_USERNAME "/feeds/light2");
Adafruit_MQTT_Subscribe light3 = Adafruit_MQTT_Subscribe(&mqtt, AIO_USERNAME "/feeds/light3");
Adafruit_MQTT_Subscribe light4 = Adafruit_MQTT_Subscribe(&mqtt, AIO_USERNAME "/feeds/light4");
/*************************** Sketch Code ************************************/
// Bug workaround for Arduino 1.6.6, it seems to need a function declaration
// for some reason (only affects ESP8266, likely an arduino-builder bug).
void MQTT_connect();
void setup() {
pinMode(LIGHT_PIN1, OUTPUT);
pinMode(LIGHT_PIN2, OUTPUT);
pinMode(LIGHT_PIN3, OUTPUT);
pinMode(LIGHT_PIN4, OUTPUT);
Serial.begin(115200);
delay(10);
Serial.println(F("Adafruit MQTT demo"));
// Connect to WiFi access point.
Serial.println(); Serial.println();
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());
// Setup MQTT subscription for onoff.
mqtt.subscribe(&light1);
mqtt.subscribe(&light2);
mqtt.subscribe(&light3);
mqtt.subscribe(&light4);
}
uint32_t x=0;
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' busy subloop
// try to spend your time here
Adafruit_MQTT_Subscribe *subscription;
while ((subscription = mqtt.readSubscription(5000))) {
// Check if its the onoff button feed Light1
if (subscription == &light1) {
Serial.print(F("On-Off button: "));
Serial.println((char *)light1.lastread);
if (strcmp((char *)light1.lastread, "OFF") == 0) {
digitalWrite(LIGHT_PIN1, LOW);
}
if (strcmp((char *)light1.lastread, "ON") == 0) {
digitalWrite(LIGHT_PIN1, HIGH);
}
}
// Check if its the onoff button feed Light2
if (subscription == &light2) {
Serial.print(F("On-Off button: "));
Serial.println((char *)light2.lastread);
if (strcmp((char *)light2.lastread, "OFF") == 0) {
digitalWrite(LIGHT_PIN2, LOW);
}
if (strcmp((char *)light2.lastread, "ON") == 0) {
digitalWrite(LIGHT_PIN2, HIGH);
}
}
// Check if its the onoff button feed Light3
if (subscription == &light3) {
Serial.print(F("On-Off button: "));
Serial.println((char *)light3.lastread);
if (strcmp((char *)light3.lastread, "OFF") == 0) {
digitalWrite(LIGHT_PIN3, LOW);
}
if (strcmp((char *)light3.lastread, "ON") == 0) {
digitalWrite(LIGHT_PIN3, HIGH);
}
}
// Check if its the onoff button feed Light4
if (subscription == &light4) {
Serial.print(F("On-Off button: "));
Serial.println((char *)light4.lastread);
if (strcmp((char *)light4.lastread, "OFF") == 0) {
digitalWrite(LIGHT_PIN4, LOW);
}
if (strcmp((char *)light4.lastread, "ON") == 0) {
digitalWrite(LIGHT_PIN4, HIGH);
}
}
}
// ping the server to keep the mqtt connection alive
if(! mqtt.ping()) {
mqtt.disconnect();
}
}
// Function to connect and reconnect as necessary to the MQTT server.
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 5 seconds...");
mqtt.disconnect();
delay(5000); // wait 5 seconds
retries--;
if (retries == 0) {
// basically die and wait for WDT to reset me
while (1);
}
}
Serial.println("MQTT Connected!");
}Code and Schematic
Tutorial
Happy Coding