Smart Home Automation Using Blynk & ESP32 IoT Projects | WiFi & Manual

In this IoT project, I have shown how to make IoT based Smart Home Automation Using Blynk & ESP32 to control an 8-channel relay module from the manual switch & smartphone using the Blynk App. If the internet is not available, then you can control the home appliances from manual switches. During the article, I have shown all the steps to make this home automation system.

This ESP32 control smart relay has the following features:
1. Control home appliances with WiFi (Blynk App)

2. Control home appliances with manual switches.

3. Monitor real-time feedback in the Blynk App.

4. Control home appliances manually without internet.

You need just an 8-channel relay module & ESP32 board to make this smart home project.

1. Relays 5v (SPDT) (8 no)

2. BC547 Transistors (8 no)

3. PC817 Optocuplors (8 no)

4. 510-ohm 0.25-watt Resistor (8 no) (R1 - R8)

5. 1k 0.25-watt Resistors (10 no) (R9 - R18)

6. LED 5-mm (10 no)

7. 1N4007 Diodes (8 no) (D1 - D8)

8. Push Buttons (8 no)

9. Terminal Connectors

10. 5V DC supply

This is the complete circuit diagram for this home automation project. I have explained the circuit in the tutorial video.

The circuit is very simple, I have used the GPIO pins D23, D22, D21, D19, D18, D5, D25 & D26 to control the 8 relays.

And the GPIO pins D13, D12, D14, D27, D33, D32, D15 & D4 connected with push buttons to control the 8 relays manually.

I have used the INPUT_PULLUP function in Arduino IDE instead of using the pull-up resistors.

I have used a 5V mobile charger to supply the smart relay module.

If the ESP32 module is connected with the WiFi, then you can control the home appliances from Blynk App and push-buttons. You can control, monitor the real-time status of the relays from anywhere in the world with the Blynk App.

If the WiFi is not available, you can control the relays from the pushbuttons.

The ESP32 will check for the WiFi after every 3 seconds. When the WiFi is available, the ESP32 will automatically connect with the WiFi.

1. Install the Blynk App from the Google play store or App store. Then create an account and tap on the New Project.

2. Give the name to the project, select ESP32 Dev Board, Connection type will be WiFi. Then tap on Create.

3. Blynk will send an authentication token to the registered email id. Tap on OK.

Then add 8 button widgets to control the 8 relays. Here I have used virtual pins V1, V2, V3, V4, V5, V6, V7, V8 for 8 buttons. And mode will be Switch.

I have explained all the details in the tutorial video.

In the Tutorial video, I have explained all the steps to program the ESP32 DEV KIT V1 using Arduino IDE.

Before uploading the code you have to install the ESP32 board and Blynk library.

Then enter the WiFi name, WiFi password & Blynk Auth Token in the code.

Select the DOIT ESP32 DEVKIT V1 board and proper PORT.

Then upload the code to ESP32 Board.

While uploading the code to ESP32, if you see the "Connecting....___" text, then press the BOOT button of the ESP32.

To make the circuit compact and give a professional look, I have designed the PCB after testing all the features of the smart relay module on the breadboard.

You can download the PCB Gerber file of this home automation project from the following link:

https://drive.google.com/uc?export=download&id=1Y8rXnczq6baxAKOrBEE8aro-uqcK0J93

After downloading the Garber file you can easily order the PCB
1. Visit https://jlcpcb.com and Sign in / Sign up

2. Click on the QUOTE NOW button.

3 Click on the "Add your Gerber file" button. Then browse and select the Gerber file you have downloaded.

4. Set the required parameter like Quantity, PCB masking color, etc

5. After selecting all the Parameters for PCB click on SAVE TO CART button.

6. Type the Shipping Address.

7. Select the Shipping Method suitable for you.

8. Submit the order and proceed for the payment.

You can also track your order from the JLCPCB.com. My PCBs took 2 days to get manufactured and arrived within a week using the DHL delivery option. PCBs were well packed and the quality was really good at this affordable price.

After that, I have soldered all the components as per the circuit diagram.

Then connect the ESP32 board with PCB

After uploading the code, if the ESP32 connects with the WiFi, the blue LED will turn on.

Then you can control the relay module from Blynk App and push-button.

Connect the 8 home appliances as per the circuit diagram. Please take proper safety precautions while working with high voltage.

Connect 5-volt DC supply with the PCB. (I have used my old mobile charger)

Turn on the 110V/230V supply and 5V DC supply.

Now you can control your home appliances in a smart way.
I hope you have liked this home automation project. I have shared all the required information for this project. I will really appreciate it if you share your valuable feedback.

Also if you have any query please write in the comment section. Thank you & Happy Learning.