Project Hub /IoT & Connected Devices/Smart Home & Building Automation/ESP32 Smart Home Automation using Alexa and Google Assistant

Intermediate

ESP32

₹500 – ₹1,500

3 – 6 Hours

Partial Kit

ESP32 Smart Home Automation using Alexa and Google Assistant

Build a smart home automation system using an ESP32 and Sinric Pro to control appliances with Amazon Alexa, Google Assistant, and physical manual switches.

Originally published on CircuitDigest

View original tutorial

Parts You'll Need

This project is sourced from another site, not written by us — this list is our best match of their components against what we stock, not a verified bill of materials. Always check the original blog (linked above) for the actual parts list before buying.

ESP32 WiFi+Bluetooth CP2102 Development Board Rs. 520.00
5V 1 Channel Relay Module Rs. 87.00
2-Slot 18650 Holder with Protective Cover and On/Off Switch – Case Rs. 109.00
MB102 Adjustable Breadboard Power Supply Module (3.3V & 5V) for Arduino & Raspberry Pi Rs. 139.00
10pcs 5mm RED Diffused Light Emitting Diodes - LEDs Set Rs. 39.00
Jumper Wire 10 Pin Male To Male 20cm Rs. 45.00
400 Points Mini Solderless Prototype PCB Breadboard High Quality Rs. 89.00
Jumper Wire 10 Pin Male To Female 20cm Rs. 45.00

Selected: Rs. 0.00

We don't carry yet: 5V - 2A AC

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How It Works

The ESP32 Smart Home Automation system integrates traditional electrical wiring with modern cloud-based IoT protocols to provide dual-control functionality for home appliances. At the heart of the system is the ESP32 Development Board, which connects to a local Wi-Fi network and establishes a persistent WebSocket connection to the SinricPro cloud platform. When a user issues a voice command via Amazon Alexa or Google Assistant, the cloud platform translates the request and communicates with the ESP32 via the SinricPro and ArduinoJson libraries. Upon receiving the digital state change command, the ESP32 toggles one of its digital output pins HIGH or LOW. This output pin drives the control terminal of a 1-channel 5V SPDT Relay Module. The relay acts as an electrically isolated switch: when triggered by the low-voltage microcontroller signal, its internal electromagnetic coil switches the high-voltage contacts, physically opening or closing the AC mains circuit connected to the light bulb. Powering the entire low-voltage control circuit is a 5V 2A AC/DC Switched-Mode Power Supply (SMPS), which steps down household AC voltage to a stable 5V DC rail required by the ESP32 and relay module. Additionally, a manual wall switch is wired in parallel or to digital sensing pins, allowing users to override or toggle the relay state locally without relying solely on internet connectivity, ensuring the appliance remains functional even during network outages.

Why Build This

Gain practical undergraduate-level experience bridging low-voltage embedded microcontrollers with high-voltage AC mains circuits using isolated relays and SMPS power supplies.

Implement cloud-based Internet of Things (IoT) architectures by integrating third-party voice assistant APIs like Amazon Alexa and Google Assistant with custom hardware.

Design robust hybrid control systems that successfully merge modern wireless automation protocols with traditional physical manual wall switches.

Real-World Application

Smart home retrofit for controlling legacy lighting, fans, and appliances via voice assistants and mobile apps while retaining traditional manual wall switch functionality.

Skills You'll Learn

Wi-Fi networking configuration

WebSockets communication

cloud IoT platform integration

JSON data parsing

relay module interfacing

AC/DC power supply integration

safe high-voltage switching

dual-control logic programming

Safety Precautions

Working with AC mains requires prior knowledge and experience. Please be careful, maintain proper distance and insulation between phase and neutral lines, and take adult supervision if needed.

Technology Tags

ESP32

WIFI

IOT

ALEXA

GOOGLE ASSISTANT

SINRIC PRO

RELAY MODULE

HOME AUTOMATION

ARDUINO

Frequently Asked Questions

Can I still use my normal wall switch to turn on the light if the internet goes down?

Yes. The system is designed to accommodate a physical manual switch alongside the automated relay, allowing local control of the appliance regardless of network status.

Do I need any special software to program the ESP32 for this project?

Yes, you will use the Arduino IDE along with the ESP32 Board Package and several specific libraries including SinricPro, WebSockets, and ArduinoJson.

Why is a 5V - 2A AC/DC SMPS required instead of just powering the ESP32 through a computer USB port?

While a USB cable is useful during initial code programming, a dedicated SMPS is necessary for permanent deployment to safely step down household AC mains voltage to provide a stable 5V DC power source for both the ESP32 and the relay module.

Gallery

This page is part of Kitkraft's Project Hub — a curated collection of electronics & robotics projects gathered from the maker community to help students and hobbyists discover and learn to build. Kitkraft does not claim authorship of the original project, and makes no representation as to the accuracy, completeness or safety of third-party source material. The summary and "How It Works" explanation above are AI-generated, rewritten with reference to the original tutorial — not a reproduction of it. Full credit and a direct link to the original source are provided above. If you're the original creator and have a concern about how your work is represented here, please contact us and we'll address it promptly.

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