HOME AUTOMATION USING BLYNK APPLICATION

INTRODUCTION :

The Home Automation system is used to perform the bulk of electronic and electrical tasks at home easily and effectively. It uses a combination of software and hardware to control different appliances at home. Home automation not used to reduce human effort but also used to utilize energy efficiently and saves time.So here we areperforming home automation using Blynk application and NodeMCU.

COMPONENTS REQUIRED:

HARDWARE

• NodeMCUdevelopment board.
• 4 channel Relay.
• USB cable.
• Connecting wires.

SOFTWARE

• Blynk app.
• Arduino IDE.

NodeMCUDEVELOPMENT BOARD:

NodeMCU is very popular inHome Automation. It is a development board consists of the ESP8266wifi module. It consists of many input/output pins, some pins support serial communication and some I2C communication. NodeMCU has a micro USB port to program it using a USB cable. Youcan also use the ESP32 development board which has more Analog and digital pins. Here we are using NodeMCU. If you want to know more about NodeMCU, (click here).

NodeMCU PINOUT:

FIG.1: NodeMCU DEVELOPMENT BOARD

BLYNK APP:

Blynk is a mobile application that has its server to process users’ requests. It is an open-source application and anybody can use it in your Home Automation system to control various devices. It is a digital dashboard where you can build a graphic interface for your project just by dragging and dropping widgets.

You can download this app from the play store.

WORKING OF RELAY MODULE:

Relay is a simple switch that is operated with both electrically and mechanically. There are 6 pins in a 1 channel relay module. they are

• VCC
• GND
• SIGNAL
• COM (COMMON)
• NO (NORMALLY OPEN)
• NC (NORMALLY CONNECTED)

As you can see in the above fig there is a switch like a thing inside a relay module.

One end of the module is connected to the COM pin and another end to either NC/NO pin.

When no voltage is supplied to the signal pin then switch remain in NO position. When we supply voltage to signal pin then switch shifts to NC position.

DIAGRAM EXPLANATION:

• Connect the D0 pin of NodeMCU to the D1 pin of the 4 channel Relay board.
• Connect the D1 pin of NodeMCU to the D2 pin of the 4 channel Relay board.
• Connect the D2 pin of NodeMCU to the D3 pin of the 4 channel Relay board.
• Connect the D3 pin of NodeMCU to the D4 pin of the 4 channel Relay board.
• Connect 3.3V  pin of NodeMCU to VCC pin of 4 channel relay board.
• Connect the GND pin of NodeMCU to the GND pin of 4 channel relay board.

Creating the Home Automation Project In BLYNK APP:

• If you are a new user you have created an account and old user just login in into your account.
• Create a new project and choose the device as NodeMCU, connection type as wifi and click “create” icon.
• After the creation of the project app will send an authentication code to your email id.

• Now click on the ‘+’ icon on the top right corner. Select 4 buttons to control the relay.
• Tap on the button and make the required changes and select D0 as an output pin and select the mode as a switch. Repeat the same with other buttons.

Home Automation Code:

#define BLYNK_PRINT Serial
 
#include
#include
 
char auth[] = "YourAuthToken";
 
char ssid[] = "YourNetworkName";
char pass[] = "YourPassword";
 
void setup()
{
Serial.begin(9600);
Blynk.begin(auth, ssid, pass);
}
 
void loop()
{
Blynk.run();
}

 

WORKING:

When the user clicks the button in the app, then the information is sent to NodeMCU via WiFi. NodeMCU analyses the received information and turn ON/OFF the respective devices through 4 channel relay.