Home Automation System Using Nodemcu ESP8266

Home automation evolution starts with some basic ideas. It minimizes the human efforts and it can be deployed in a lot of fields like military, surveillance application is developed in the modern world.

In this tutorial, we’ll learn how to build a basic automation system using NodeMCU ESP8266. Lets began with step by step guide that describes in this video:

Hardware Components

You need the following hardware assets for your automation project:

S.NO	Components	Value	Qty
1.	PCB For Home Automation Circuit	–	1
2.	Relays	5v/6v	4
3.	Male/Female Header	–	1
4.	5mm Terminal block	–	4
5.	NPN Transistor	BC547	4
6.	Diode	1N4007	4
7.	Resistor	330ohm	5
8.	Electrolyte Capacitor	1uF	1
9.	LED	5mm	5
10.	Nodemcu	ESP8266	1
11.	5v Regulator IC	LM7805	1

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Useful Steps

(1) Soldering of PCB

• Solder Terminal Block
• Solder Output LED’s and Diode’s
• Solder Relay’s
• Solder Transistors and 330 Ohm Resistors
• Solder Male and Female Header’s
• Solder DC Connector, Regulator, Capacitors, etc

(2) Setting Up Arduino IDE

• Download both libraries and include it in Arduino IDE

(3) Setting Up Firebase

• Search for Firebase
• Log in with your G mail ID
• Add New Project
• Goto Database ➞ Rules ➞ and define Read/Write rules as public
• Copy Database URL and Update in Arduino Code .. remove https & /
• Now go to project overview ➞ project setting ➞ service accounts ➞ database secrets
• Copy Authentication code and update it in Arduino IDE
• Update Wifi SSID and Password
• Upload Code to NodeMCU

(4) Making an IoT App

• Search for MIT App Inventor 2
• Login with your Gmail id
• Upload AI file from the link in the description
• Click on Firebase Icon
• Update Firebase URL & Authentication code
• Now make changes according to your requirement and Export APK file

(5) Test Circuit

• Power Up the circuit with DC-12V Adapter
• Connect AC load at the output of terminal blocks

Code:

#include 
#include 
#define FIREBASE_HOST "basic-2db74.firebaseio.com"                  // Your Firebase Project URL goes here without "http:" , "\" and "/"
#define FIREBASE_AUTH "WljQ8JpTdYqUAnp7VCPgcOshaL90zJtvW83NHAov"    // Your Firebase Database Secret goes here
#define WIFI_SSID "TP-LINK_CD2ED6"                                  // your WiFi SSID for which yout NodeMCU connects
#define WIFI_PASSWORD "20244064"                                    // your WiFi PASSWORD

#define Relay1 D0
int val1;

#define Relay2 D1 
int val2;

#define Relay3 D2 
int val3;

#define Relay4 D3
int val4;

void setup() 
{
  Serial.begin(115200);                                                   // Select the same baud rate if you want to see the datas on Serial Monitor
  pinMode(Relay1,OUTPUT);
  pinMode(Relay2,OUTPUT);
  pinMode(Relay3,OUTPUT);
  pinMode(Relay4,OUTPUT);

  digitalWrite(Relay1,HIGH);
  digitalWrite(Relay2,HIGH);
  digitalWrite(Relay3,HIGH);
  digitalWrite(Relay4,HIGH);

  WiFi.begin(WIFI_SSID,WIFI_PASSWORD);
  Serial.print("connecting");
  while (WiFi.status()!=WL_CONNECTED){
    Serial.print(".");
    delay(500);
  }
  Serial.println();
  Serial.print("connected:");
  Serial.println(WiFi.localIP());

  Firebase.begin(FIREBASE_HOST);
  Firebase.setInt("S1",0);                     //Here the varialbe"S1","S2","S3" and "S4" needs to be the one which is used in our Firebase and MIT App Inventor
  Firebase.setInt("S2",0); 
  Firebase.setInt("S3",0); 
  Firebase.setInt("S4",0); 
  
}
void firebasereconnect()
{
  Serial.println("Trying to reconnect");
    Firebase.begin(FIREBASE_HOST);
  }

void loop() 
{
  if (Firebase.failed())
      {
      Serial.print("setting number failed:");
      Serial.println(Firebase.error());
      firebasereconnect();
      return;
      }
      
  val1=Firebase.getString("S1").toInt();                                        //Reading the value of the varialble Status from the firebase
  
  if(val1==1)                                                             // If, the Status is 1, turn on the Relay1
     {
      digitalWrite(Relay1,LOW);
      Serial.println("Relay 1 ON");
    }
    else if(val1==0)                                                      // If, the Status is 0, turn Off the Relay1
    {                                      
      digitalWrite(Relay1,HIGH);
      Serial.println("Relay 1 OFF");
    }

  val2=Firebase.getString("S2").toInt();                                        //Reading the value of the varialble Status from the firebase
  
  if(val2==1)                                                             // If, the Status is 1, turn on the Relay2
     {
      digitalWrite(Relay2,LOW);
      Serial.println("Relay 2 ON");
    }
    else if(val2==0)                                                      // If, the Status is 0, turn Off the Relay2
    {                                      
      digitalWrite(Relay2,HIGH);
      Serial.println("Relay 2 OFF");
    }

   val3=Firebase.getString("S3").toInt();                                        //Reading the value of the varialble Status from the firebase
  
  if(val3==1)                                                             // If, the Status is 1, turn on the Relay3
     {
      digitalWrite(Relay3,LOW);
      Serial.println("Relay 3 ON");
    }
    else if(val3==0)                                                      // If, the Status is 0, turn Off the Relay3
    {                                      
      digitalWrite(Relay3,HIGH);
      Serial.println("Relay 3 OFF");
    }

   val4=Firebase.getString("S4").toInt();                                        //Reading the value of the varialble Status from the firebase
  
  if(val4==1)                                                             // If, the Status is 1, turn on the Relay4
     {
      digitalWrite(Relay4,LOW);
      Serial.println("Relay 4 ON");
    }
    else if(val4==0)                                                      // If, the Status is 0, turn Off the Relay4
    {                                      
      digitalWrite(Relay4,HIGH);
      Serial.println("Relay 4 OFF");
    }    
}

Circuit Diagram

Download all important files & useful materials for this project from the link below.