Subhajit
Published © GPL3+

Arduino IoT Cloud ESP8266 NodeMCU Alexa Home Automation 2021

How to make an IoT-based Smart Home with Arduino IoT Cloud & Alexa using NodeMCU ESP8266 to control 4 home appliances with voice commands.

IntermediateFull instructions provided10 hours14,749
Arduino IoT Cloud ESP8266 NodeMCU Alexa Home Automation 2021

Things used in this project

Hardware components

NodeMCU ESP8266 Breakout Board
NodeMCU ESP8266 Breakout Board
×1
4-CHANNEL RELAY CONTROLLER FOR I2C
ControlEverything.com 4-CHANNEL RELAY CONTROLLER FOR I2C
×1
Pushbutton switch 12mm
SparkFun Pushbutton switch 12mm
×1

Software apps and online services

Arduino IoT Cloud
Arduino IoT Cloud
Alexa Voice Service
Amazon Alexa Alexa Voice Service
Arduino IDE
Arduino IDE

Hand tools and fabrication machines

Soldering iron (generic)
Soldering iron (generic)

Story

Read more

Schematics

Circuit of Arduino IoT Cloud ESP8266 control Relay with switches

Circuit of Arduino IoT Cloud ESP8266 Control Relays with switches

Code

Sketch of Arduino IoT Cloud ESP8266 control Relay with switches

Arduino
Keep all the 3 files in the same folder
/**********************************************************************************
 *  TITLE: Arduino IoT Cloud control 4 Relays using NodeMCU
 *  Click on the following links to learn more. 
 *  YouTube Video: https://youtu.be/UtReFcOLJx8
 *  Related Blog : https://iotcircuithub.com/esp8266-projects/
 *  by Tech StudyCell
 *  Preferences--> Aditional boards Manager URLs : 
 *  https://dl.espressif.com/dl/package_esp32_index.json, http://arduino.esp8266.com/stable/package_esp8266com_index.json
 *  
 *  Download Board ESP8266 NodeMCU : https://github.com/esp8266/Arduino
 *  Download the libraries
 *  ArduinoIoTCloud Library with all the dependencies
 **********************************************************************************/


#include "arduino_secrets.h"
#include "thingProperties.h"

// define the GPIO connected with Relays and switches
#define RelayPin1 5  //D1
#define RelayPin2 4  //D2
#define RelayPin3 14 //D5
#define RelayPin4 12 //D6

#define SwitchPin1 10  //SD3
#define SwitchPin2 0   //D3 
#define SwitchPin3 13  //D7
#define SwitchPin4 3   //RX

#define wifiLed   16   //D0

int toggleState_1 = 0; //Define integer to remember the toggle state for relay 1
int toggleState_2 = 0; //Define integer to remember the toggle state for relay 2
int toggleState_3 = 0; //Define integer to remember the toggle state for relay 3
int toggleState_4 = 0; //Define integer to remember the toggle state for relay 4

void relayOnOff(int relay) {

  switch (relay) {
    case 1:
      if (toggleState_1 == 0) {
        digitalWrite(RelayPin1, LOW); // turn on relay 1
        toggleState_1 = 1;
        Serial.println("Device1 ON");
      }
      else {
        digitalWrite(RelayPin1, HIGH); // turn off relay 1
        toggleState_1 = 0;
        Serial.println("Device1 OFF");
      }
      delay(100);
      break;
    case 2:
      if (toggleState_2 == 0) {
        digitalWrite(RelayPin2, LOW); // turn on relay 2
        toggleState_2 = 1;
        Serial.println("Device2 ON");
      }
      else {
        digitalWrite(RelayPin2, HIGH); // turn off relay 2
        toggleState_2 = 0;
        Serial.println("Device2 OFF");
      }
      delay(100);
      break;
    case 3:
      if (toggleState_3 == 0) {
        digitalWrite(RelayPin3, LOW); // turn on relay 3
        toggleState_3 = 1;
        Serial.println("Device3 ON");
      } else {
        digitalWrite(RelayPin3, HIGH); // turn off relay 3
        toggleState_3 = 0;
        Serial.println("Device3 OFF");
      }
      delay(100);
      break;
    case 4:
      if (toggleState_4 == 0) {
        digitalWrite(RelayPin4, LOW); // turn on relay 4
        toggleState_4 = 1;
        Serial.println("Device4 ON");
      }
      else {
        digitalWrite(RelayPin4, HIGH); // turn off relay 4
        toggleState_4 = 0;
        Serial.println("Device4 OFF");
      }
      delay(100);
      break;
    default : break;
  }
}

void manual_control() {
  //Manual Switch Control
  if (digitalRead(SwitchPin1) == LOW) {
    delay(200);
    relayOnOff(1);
  }
  else if (digitalRead(SwitchPin2) == LOW) {
    delay(200);
    relayOnOff(2);
  }
  else if (digitalRead(SwitchPin3) == LOW) {
    delay(200);
    relayOnOff(3);
  }
  else if (digitalRead(SwitchPin4) == LOW) {
    delay(200);
    relayOnOff(4);
  }
}

void setup() {
  // Initialize serial and wait for port to open:
  Serial.begin(9600);
  // This delay gives the chance to wait for a Serial Monitor without blocking if none is found
  delay(1500);

  // Defined in thingProperties.h
  initProperties();

  // Connect to Arduino IoT Cloud
  ArduinoCloud.begin(ArduinoIoTPreferredConnection);

  setDebugMessageLevel(2);
  ArduinoCloud.printDebugInfo();

  pinMode(RelayPin1, OUTPUT);
  pinMode(RelayPin2, OUTPUT);
  pinMode(RelayPin3, OUTPUT);
  pinMode(RelayPin4, OUTPUT);

  pinMode(wifiLed, OUTPUT);

  pinMode(SwitchPin1, INPUT_PULLUP);
  pinMode(SwitchPin2, INPUT_PULLUP);
  pinMode(SwitchPin3, INPUT_PULLUP);
  pinMode(SwitchPin4, INPUT_PULLUP);

  //During Starting all Relays should TURN OFF
  digitalWrite(RelayPin1, HIGH);
  digitalWrite(RelayPin2, HIGH);
  digitalWrite(RelayPin3, HIGH);
  digitalWrite(RelayPin4, HIGH);

  digitalWrite(wifiLed, HIGH);  //Turn OFF WiFi LED
}

void loop() {
  ArduinoCloud.update();
  
  manual_control(); //Control relays manually

  if (WiFi.status() != WL_CONNECTED)
  {
    digitalWrite(wifiLed, HIGH); //Turn OFF WiFi LED
  }
  else{
    digitalWrite(wifiLed, LOW); //Turn ON WiFi LED
  }
}

void onSwitch1Change() {
  if (switch1 == 1)
  {
    digitalWrite(RelayPin1, LOW);
    Serial.println("Device1 ON");
    toggleState_1 = 1;
  }
  else
  {
    digitalWrite(RelayPin1, HIGH);
    Serial.println("Device1 OFF");
    toggleState_1 = 0;
  }
}

void onSwitch2Change() {
  if (switch2 == 1)
  {
    digitalWrite(RelayPin2, LOW);
    Serial.println("Device2 ON");
    toggleState_2 = 1;
  }
  else
  {
    digitalWrite(RelayPin2, HIGH);
    Serial.println("Device2 OFF");
    toggleState_2 = 0;
  }
}

void onSwitch3Change() {
  if (switch3 == 1)
  {
    digitalWrite(RelayPin3, LOW);
    Serial.println("Device2 ON");
    toggleState_3 = 1;
  }
  else
  {
    digitalWrite(RelayPin3, HIGH);
    Serial.println("Device3 OFF");
    toggleState_3 = 0;
  }
}

void onSwitch4Change() {
  if (switch4 == 1)
  {
    digitalWrite(RelayPin4, LOW);
    Serial.println("Device4 ON");
    toggleState_4 = 1;
  }
  else
  {
    digitalWrite(RelayPin4, HIGH);
    Serial.println("Device4 OFF");
    toggleState_4 = 0;
  }
}

thingProperties.h

Arduino
keep this file with the main code
// Code generated by Arduino IoT Cloud, DO NOT EDIT.


#include <ArduinoIoTCloud.h>
#include <Arduino_ConnectionHandler.h>


const char THING_ID[]           = "THING ID";  //Enter THING ID
const char DEVICE_LOGIN_NAME[]  = "DEVICE ID"; //Enter DEVICE ID

const char SSID[]               = SECRET_SSID;    // Network SSID (name)
const char PASS[]               = SECRET_PASS;    // Network password (use for WPA, or use as key for WEP)
const char DEVICE_KEY[]  = SECRET_DEVICE_KEY;    // Secret device password

void onSwitch1Change();
void onSwitch2Change();
void onSwitch3Change();
void onSwitch4Change();

CloudSwitch switch1;
CloudSwitch switch2;
CloudSwitch switch3;
CloudSwitch switch4;

void initProperties(){

  ArduinoCloud.setBoardId(DEVICE_LOGIN_NAME);
  ArduinoCloud.setSecretDeviceKey(DEVICE_KEY);
  ArduinoCloud.setThingId(THING_ID);
  ArduinoCloud.addProperty(switch1, READWRITE, ON_CHANGE, onSwitch1Change);
  ArduinoCloud.addProperty(switch2, READWRITE, ON_CHANGE, onSwitch2Change);
  ArduinoCloud.addProperty(switch3, READWRITE, ON_CHANGE, onSwitch3Change);
  ArduinoCloud.addProperty(switch4, READWRITE, ON_CHANGE, onSwitch4Change);

}

WiFiConnectionHandler ArduinoIoTPreferredConnection(SSID, PASS);

arduino_secrets.h

Arduino
Keep this file in the same folder with the main code
#define SECRET_SSID "WIFI NAME"  //Enter WIFI NAME
#define SECRET_PASS "WIFI PASSWORD"  //Enter WIFI PASSWORD
#define SECRET_DEVICE_KEY "SECRET KEY"  //Enter Secret Key

Credits

Subhajit

Subhajit

47 projects • 127 followers
I have studied Electrical Engineering. I do love to make different DIY electronics projects & share it on my YouTube channel Tech StudyCell.

Comments

Related channels and tags
  • Amazon Alexa
  • ControlEverything.com
  • Espressif
  • Home Automation
  • Internet of Things
  • NodeMCU
  • SparkFun
  • Voice