Introduction: Home Automation Using Blynk

About: I am a tech enthusiast who loves to build something all the time. Stay tuned to this channel for some amazing projects

Hello, Guys! My name is Navaneeth Krishnan. But I prefer The

Tech Guy as my colleagues calls me! So, I decided to document all the projects I do, so, now that I am documenting it, I thought it would be nice to do it in a tutorial form. So, here I am making the first tutorial for you guys!

I recently came to know about “BLYNK” which caught my attention since it is a mind blowing idea and the greatest part is they provide all the greatness for free! For those who haven’t heard about or if you want to know more about it visit the link below.

And one more thing before I start the instructable, all the projects I am writing will be for sale.For now, the products is for sale only in India, but I will try my best to take it international. And the link to this project is given below:


So, let me start off by saying what this project exactly is!

When you are done with this you will be able to connect your appliances to the world of internet (now-a-days called as IoT: Internet of Things) and control them from any where in the world.

For instance imagine you are on a vacation and suddenly you have a problem remembering whether you closed your garage door or not. No problem, with this project you will be able to close your garage door while enjoying your holiday at a beach resort having nice cup of tea. And ofcourse you will have the fun working with boards and codes and all….

Step 2: Working

The hardware consists of a development board based on wifi module

esp8266 called WeMos D1 which is arduino compatible and can be programmed using arduino IDE.A four channel relay is connected to the wemos and wemos connects to the free server provided by blynk to receive the commands send from the app made with blynk with symple drag n drop feature. So basically, the app recieves input from the user and sends to the server and the server sends it to your project hardware which is connected to internet via Wi-Fi (you can also used ethernet with arduino and an ethernet sheild) which the server identifies with the unique authtoken that you receive for every project that you make.

Step 3: Materials Required

1. WeMos D1 R2.

2. a 4-channel relay.

Step 4: Setting Up the Hardware

Connect the VCC pin of the relay to the appropriate voltage(+5V or +12V)and GND pin to the GND pin of the WeMos D1. Now connect the 4 input pins to pins D2, D3, D4, D5 of the WeMos D1.That’s it you are all set to go. You connect your appliances the relay.

Step 5: The Hardware Code

For this, you will need Arduino IDE, which can be downloaded from the link below:


After you are done with that you will have to do a couple of tinkering before you can start to upload the code.

1. You will need to download and install e sp8266 board files for Arduino IDE.

2. Install the BLYNK library.

Once, you have finished the above two steps, you can download the code attached below and upload to your WeMos D1(Note: Don’t forget to change the board to your WeMos before that.)

That’s it you are ready for the next step!

Step 6: The Blynk App

For blynk, the problem I was facing that I had to manually input the wifi SSID, wifi password and the auth token into the code itself and with a simple hack you can solve this issue. This hack was actually provided by one of the co-founders of blynk itself so you don’t need to feel guilty.

If you haven’t already, download the Blynk App from the Google Play store. Then open it, create an account and log in.

Or, if you already have the Blynk app installed on your phone, make sure it’s updated to the latest release!(P.S. It is both available for android and IOS).

Now, Open the app and create a new blynk account with your google account or facebook(I personally prefer Facebook, it is a lot more easier!).Click the QR-code icon in the top-right corner of the Blynk app (or the bigger icon on the main screen).and scan the QR code given in the images.(follow the screenshots ) That’s it you have done with the app setup too. Now, it's time to test the project.

Step 7: Testing

First turn the hardware on and make sure all the connections are correct. Now open the blynk project and follow the screen shot to set up your hardware to your wifi network.

After you have setup your hardware, click the play button
the top right corner to start the project.

Now, You can control your appliances from anywhere in the world.

If you run into any problem look up the next step

Step 8: Troubleshooting

1. Double Check all the connections

2. Make sure the appropriate amount voltage is connected.

3. Make sure the internet is available.

4. Make sure you select the wifi router and give the correct password.

Internet of Things Contest 2017

Participated in the
Internet of Things Contest 2017