Relay Control Using NodeMCU Through Blynk App

Hi everyone,

Today I am here with an IoT project, which can control four home appliances though Blynk app. This project is for beginners and also for experts.

When I am on the bed, I am always lazy to turn off lights and control fan speed. For this purpose, I even call mom to do it for me..... ha... ha...

So controlling my room's light and fan through an app will be helpful for me. So I decided to design one for me. For convenience, I am using LED as home appliances. Here is how I build one for my home and do watch the video.

STEP 1

Design the circuit using circuito.io.

STEP 2

Collect the components.

STEP 3

Configure the Bynk app.

Download the Blynk app from playstore for Andriod devices.

STEP 4

Sign up with your email and password.

STEP 5

Creat a new project. The steps are given below:

STEP 6

Add widgets to the app as required, in this project we are going to control four devices. So need 4 switches. Drag and drop them for your imagination.

STEP 7

Change the logic from 0-1 to 1-0 because the output of NodeMCU is active LOW. Select digital pins D0, D1, D2 and D3 as output pins. change mode to switch from push.

STEP 8

Select the device you are going to communicate, which is the NodeMCU.

STEP 9

Send the authentication code to your e-mail.

STEP 10

Copy the authentication code from mail.

STEP 11

Set up the circuit as per the schematics.

STEP 12

Open Arduino IDE.

Configure it for NodeMCU.

#define BLYNK_PRINT Serial        
#include <ESP8266WiFi.h>        
#include <BlynkSimpleEsp8266.h>        
char auth[] = "authtocken"; // PASTE YOUR AUTHENTICATION CODE HERE        
// Your WiFi credentials.        
char ssid[] = "ssid"; //WIFI NAME        
char pass[] = "password"; //PASSWORD        
void setup()        
{        
 Serial.begin(9600);        
 Blynk.begin(auth, ssid, pass);        
}        
void loop()        
{        
 Blynk.run();        
}        
        

STEP 13

Upload the code.

STEP 14

Open serial monitor to check whether NodeMCU is paired with your WiFi.

STEP 15

Run the Blynk app.

STEP 16

Tap the buttons to turn the LEDs on and off.

Thank you!