Introduction: Internet Control for Turning Computer ON/Off Using Blynk
We all have imagined about controlling our home pc from all over the world and apps like team viewer and remote desktop helps us to fulfill it up to an extent but they do not give us all the provision, we can only control a pc that is already turned on....this tutorial helps you to remove that barrier
MATERIALS REQUIRED:
1. Arduino
2. Two relay boards or a board with two relays.
3. ESP8266( Wi-Fi module )
4.jumper wires
5. A smartphone with blank app
6. And of course , a computer
Step 1: Blynk
first setup the blank app, you install it from the play store. Now create a new project select your device(mine is arduino mega) and connection as Wi-Fi . Add two buttons and set the values as given in the picture.
Note: the values sent (0 and 1) my relay board turns on on low and off on high but if yours turn on high and turn off on low, you should interchange the values.
Step 2: Connections
Connect the Wi-Fi module ESP8266 to the arguing as
Vcc to 5v
Gnd to gnd
Tx to rx
Rx to tx
Connect the relay board as following
Relay board 1
Vcc to 5v
Gnd to gnd
I/p to pin 2
Relay board 2
Vcc to 5v
Gnd to gnd
I/p to pin 3
Step 3: Arduino Code
The arduino code is a simple basic blynk code for n ESP8266 shield you can download the blank library from their official site or you can click the link below...
Change the authtoken to that you received in your mail from blynk
And said to your Wi-Fi name and add the the password also...
https://github.com/blynkkk/blynk-library/releases/latest
Attachments
Step 4: Testing
The test was ssuccessful and pictures are given below.
I will shortly upload a full video tutorial with testing.

Participated in the
Microcontroller Contest 2017
9 Comments
1 year ago on Introduction
Hey , i am also doing this thing for my project. I am facing issues connecting my relay switch to computer motherboard. Can you please post detailed images showing how to connect relay module outer section with the front panel of the motherboard
Question 1 year ago on Step 3
please can you shoot a video about how connections is done between arduino , computer, wifi module, relay switch
Question 2 years ago
Hello thank you so much. Will the user will know in the application if the computer was already TURN OFF/ON ? Where can we watch the video of the whole process on how to create the whole project?
4 years ago
How to do the connections from arduino to the Computer ?
Can anybody explain in detail about the pin connections from arduino to the PC as the pics above are not clear.
Admin can you please upload the video for the whole procedure as it will be easy for us to understand.
Thanks in advance.
Reply 4 years ago
Please elaborate specifically the connections from the relay to the PC's power supply connections.
4 years ago
Hi,
I'm using an nodemcu and getting this constant message on my computer and can't connect to the app.
[5001] Connecting to blynk-cloud.com:8442
[17602] Connecting to blynk-cloud.com:8442
[30709] Connecting to blynk-cloud.com:8442
[43919] Connecting to blynk-cloud.com:8442
[57026] Connecting to blynk-cloud.com:8442
[70031] Connecting to blynk-cloud.com:8442
Do you know how to solve it?
4 years ago
Nice one!
I just wonder why use Arduino when you can use the ESP8266 (especially NodeMCU) as microcontroller.
Am I right?
Reply 4 years ago
Yes... You surely can use the ESP8266 itself ... But i was having some technical issues with my serial to uart converter.... My PC is not recognizing it ...even after manually installing the driver.... As soon this problem is resloved... I will put an update for the above project
4 years ago
very smart and useful! thanks for sharing