Easy IOT based home automation system using Blynk

It is a tutorial about Iot based home automation using Blynk

How it works :

Here I make a customized circuit board to control 4 relays by esp8266 NodeMcu

This circuit runs on DC 12 volt 1 amp power.

when power on nodemcu connect to you router via WiFi & also connect with Blynk server

Your smart phone send command to Blynk server & Blynk cloud server send command to

nodemcu .

The D0,D2,D3,D4 pin of nodemcu became high or low then relay turn on or off connected Ac appliances.

You Need to make :

1. Customized pcb ( I make pcb from https://jlcpcb.com They offer 10 PCBs in $2 Download gerber file from here & upload to jlcpcb website .build time 48 hours )
2. Esp 8266 NodeMcu Lolin
3. 12v 1 amp power adapter
4. Ic 7805 - 1 pcs
5. Transistor Bc 548b - 4 pcs
6. Resistors 10K - 4 pcs & 1K - 5pcs
7. Diode IN4007 - 4pcs
8. Relay 12V - 4pcs
9. Led red - 1pcs & green - 4 pcs
10. Capacitor 470uf/25V - 1pcs
11. Female Header connector
12. Terminal block - 4pcs

Making : 

we are using professional quality PCB so making is very easy

just put all parts to pcb (All parts name printed on PCB)

Solder all components & cut extra lid of parts.

        PCB is complete 

Circuit Diagram of Iot based Home automaton System

Software Part: 

Download & install Blynk app in your android phone

sing-up to Blynk using a email id

Then create a new project & select board Nodemcu ( you can see Video)

After creating a new project Blynk will send a Authentication code in your email Id 

copy this code

Now go to your pc You need Arduino Ide to program node mcu

If you have not use Nodemcu before it ,then you have to download Esp 8266 nodemcu board from

Board manager of arduino ide (Here is a guide for add Nodemcu to arduino ide)

Then Download Blynk library from here 

  

Now open Arduino Ide go to Examples>Blynk >Boards_wifi>NodeMcu 

Just put your Auth Code (witch you received in email)   ,your Router name & password

Upload code to Nodemcu

Now open Blynk app on your phone

Add 4 buttons using pin D0,D2,D3,D4

congratulation you complete software part .

Now connect Ac appliances with circuit board .follow connection diagram below

Now plug power of 12v adapter and you can control lights or fan using Blynk app button