In this IoT project, I have shown how to make IoT-based Smart Home Automation using the new Blynk 2.0 ESP32 LDR & temperature sensor to control an 8-channel relay module from the manual switch, IR remote & smartphone using the Blynk IoT App.

During the article, I have shown all the steps to make this Blynk home automation system.

Tutorial Video on this ESP32 Blynk IoT Home Automation:

This Blynk ESP32 control smart relay has the following features:

So, you can easily make this home automation project at home just by using an ESP32 and relay module. Or you can also use a custom-designed PCB for this project.

Required Components:

Required Components for the PCB:

5V DC supply Required Software:

1. Arduino IDE 

2. Blynk IoT App Testing the Circuit Before Designing the PCB

Testing the Circuit Before Designing the PCB:

Before designing the PCB, I have made the complete circuit using ESP32, an 8-channel relay module, sensors, and manual switches.

As you can see, the relays can be controlled from the Blynk IoT app, IR remote, and manual switches.

If the WiFi is not connected with ESP32, still you can control the appliances from manual switches and IR remote.

Control Relays With Blynk IoT App:

If the ESP32 is connected with WiFi, then you can control the home appliances from Blynk IoT App.

You also use multiple smartphones to control the appliances with Blynk App. For that, you have to log in same Blynk account from all the smartphones.

In this way, all smartphones will be sink to the Blynk server. You can control, monitor the real-time status of the relays, room temperature & humidity from anywhere in the world in the Blynk IoT App.

If the ESP32 is not connected with WiFi, still you can control the appliances with IR remote and Manual Switch without internet.

ESP32 Control Relay With IR Remote:

You can always control the relays from the IR remote. For this project, you can use any IR remote.

You can monitor the real-time feedback in the Blynk IoT App.

I have explained how to get the IR codes (HEX codes) from any remote in the following steps.

Control Relays Manually With Switches:

You can also control the relays from the switches or pushbuttons.

You can monitor the real-time feedback in the Blynk IoT App.

Please refer to the circuit diagram to connect the switches.

Designing the PCB for ESP32 IoT Projects:

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:

Download the PCB Gerber File

Order the PCB from JLCPCB:

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 gerber file" button. Then browse and select the Gerber file you have downloaded.

Uploading the Gerber File and Set the Parameters:

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.

Select Shipping Address and Payment Mode:

6. Type the Shipping Address.

7. Select the Shipping Method suitable for you.

8. Submit the order and proceed with 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.

Solder All the Components on PCB:

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

Then connect the ESP32 board, DHT11 sensor, LDR, and 1838 IR receiver with PCB.

Create FREE Blynk Cloud Account:

For this smart house project, I have used the Blynk IoT Cloud Free plan.

Click on the following link to create a Blynk Cloud account.

https://blynk.cloud/dashboard/register

After that Blynk cloud dashboard will open.

Create a New Template in Blynk Cloud:

First, you have to create a template in the Blynk cloud.

You will get the BLYNK_TEMPLATE_ID and BLYNK_DEVICE_NAME after creating the temple.

The BLYNK_TEMPLATE_ID and BLYNK_DEVICE_NAME will be required while programming the ESP32.

Create a Datastream in Blynk Cloud:

After that, you have to create Datastreams. Here I will control 8 relays, so I have to create 8 Datastreams for relays and 2 Datastreams for sensors.

In a similar way, create 8 datastreams with virtual pin V1 to V8.

And for the Temperature, humidity, and LDR I have used V10, V11, & V12.

Set Up Blynk Cloud Web Dashboard:

Now go to the web dashboard tab.

Drag and drop 8 Switch widgets and 2 Level widgets.

Go to the settings of each widget, and select a Datastream.

Please refer to the tutorial video for more details.

Install Blynk IoT App to Configure Mobile Dashboard:

Add Widgets in Blynk IoT App:

Get the IR Codes (HEX Code) From Remote:

Now, to get the HEX codes from the remote, first, we have to connect the IR receiver output pin with GPIO D35.

And give the 5V across the VCC and GND. The IR receiver must have a metallic casing, otherwise, you may face issues.

Download the code for getting the HEX codes

https://drive.google.com/file/d/1MLJ96CQN3wOuu6iWArsMq9rKsKR5Z3Xi/view?usp=sharing

Then follow the following steps to get the HEX codes

Save all the HEX codes in a text file.

Program the ESP32 for This Blynk Project

Download and install the following libraries in Arduino IDE

You have to keep all the 9 files in the same folder.

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

Update the WiFi Credentials Through OTA:

After programming the ESP32, you have to update the WiFi credentials from the Blynk IoT app.

In the tutorial video, I have explained all the steps to update the WiFi credentials to ESP32 through OTA.

Connect the Home Appliances:

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.

Finally!! the Blynk Smart Home System Is Ready

Now you can control your home appliances in a smart way.

I hope you have liked this new Blynk home automation project. I have shared all the required information for this project.

I will really appreciate it if you share your valuable feedbacks. Also if you have any query please write in the comment section.

Thank you & Happy Learning.