Alexa Home Automation Using ESP32 With IR Remote & Manual Control - IoT Projects 2021

In this IoT project, I have shown how to make IoT-based ESP32 Home Automation using Alexa, IR remote, and switches to control an 8-channel relay module with and without internet. If the internet is not available, then you can control the home appliances from IR remote & manual switches. During the article, I have shown all the steps to make this home automation system.

This ESP32 control relay module has the following features:

1. Control home appliances with Alexa (voice control).
2. Control home appliances with IR Remote.
3. Control home appliances with manual switches.
4. Monitor real-time feedback in the Blynk App.
5. Control home appliances manually without internet from IR remote and switches.

If you don't want to use PCB, you can also make this IoT project using an 8-channel relay module, ESP32, and IR receiver sensor.

1. ESP32 DEVKIT
2. TSOP1838 IR receiver
3. Relays 5v (SPDT) (8 no)
4. BC547 Transistors (8 no)
5. PC817 Optocuplors (8 no)
6. 510-ohm 0.25-watt Resistor (8 no) (R1 - R8)
7. 1k 0.25-watt Resistors (10 no) (R9 - R18)
8. LED 5-mm (10 no)
9. 1N4007 Diodes (8 no) (D1 - D8)
10. Push Buttons (8 no) or Switches
11. Terminal Connectors5V DC supply
12. Any Alexa devices like ECHO DOT

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 Switches to control the 8 relays manually.

And the output pin of the IR Receiver is connected with GPIO D35.

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

I have used a 5V 5A DC power supply.

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

As you can see, the relay can be controlled from the IR Remote, manual switches, and Amazon Alexa App. In the following steps, I have explained the complete projects in detail, also shared the code and PCB Garber file. Download the code for this project.

If the ESP32 module is connected with the WiFi, you can control the home appliances from Amazon Alexa App, IR Remote, and manual switches.

You can control, monitor the real-time status of the relays in the Alexa App. The ESP32, Amazon Echo Dot should be connected to the same WiFi network.

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

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

And if the ESP32 connected with Wi-Fi, then you can also monitor the real-time feedback in the Amazon Alexa App.

If the WiFi is not available, you can also control the relays from the manual switches.

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

Please refer to the circuit diagram to connect the manual switches.

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.

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/RAB 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 with the payment. You can also track your order from 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 the PCB.

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.

Then follow the following steps to get the HEX codes

1. Install the IRremote library in Arduino IDE
2. Download the attached code, and upload it to ESP32.
3. Open Serial Monitor with Baud rate 9600.
4. Now, press the IR remote button.
5. The respective HEX code will populate in the serial monitor.

Save all the HEX codes in a text file.

If you use switch (Latched) then refer to the code for Switch, and for momentary switch please use the code for the pushbutton.

Download and install the following libraries in Arduino IDE

• IRremote Library
• AceButton Library
• Espalexa Library

I have shared the download link of all the libraries in the code.

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

Then update the HEX code in the ir_remote function as shown in the tutorial video.

After that, 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.

Open Amazon Alexa App and follow the steps:

1. Tap on Devices. Then Tap on the "+" icon.

2. Tap on "Light", then select "Others".

3. Goto Alexa and tap on "DISCOVER DEVICES". It will take a minute to add devices. During this time the ESP32 should be connected with the WiFi.

4. Tap on "Devices", and tap on "Lights" to see all the devices.

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 Amazon Alexa App.

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.

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 Alexa 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.