[TechBot] DIY Smart Home Automation System Using NodeMCU & Google Assistant

[protaa]

Project Overview:

This project is a budget-friendly smart home automation system using NodeMCU (ESP8266) that lets you control your home appliances with Google Assistant — via voice commands or smartphone using IFTTT and Blynk.

No need to buy expensive smart switches — build your own!

Purpose:

To control home appliances (like light, fan, etc.) through Google Assistant, enabling remote and voice-based automation using low-cost components.

Hardware Used:

• NodeMCU ESP8266 (Wi-Fi microcontroller)

• 2-channel Relay Module (for switching appliances)

• Jumper wires

• Breadboard or PCB

• Power supply (5V USB or adapter)

• Home appliances (e.g. bulb, fan)

• Smartphone with Google Assistant

Software & Services Used:

• Blynk app (or Blynk 2.0 platform)

• IFTTT (If This Then That)

• Google Assistant

• Arduino IDE (for uploading code)

How It Works:

1. NodeMCU connects to Wi-Fi and listens for commands via the Blynk app.

2. IFTTT is linked with Google Assistant and sends HTTP requests (Webhooks) to trigger Blynk virtual pins.

3. NodeMCU reads the Blynk command and triggers the relay, turning the appliance ON or OFF.

Wiring Diagram (Basic Example):

• D1 → IN1 (Relay 1)

• D2 → IN2 (Relay 2)

• VCC → 5V

• GND → GND

Use proper isolation when connecting AC appliances!

 

Sample Arduino Code Snippet

#define BLYNK_TEMPLATE_ID "YourTemplateID"
#define BLYNK_DEVICE_NAME "SmartHome"
#define BLYNK_AUTH_TOKEN "YourAuthToken"

#include <ESP8266WiFi.h>
#include <BlynkSimpleEsp8266.h>

char auth[] = "YourAuthToken";
char ssid[] = "YourWiFiSSID";
char pass[] = "YourWiFiPassword";

void setup() {
  pinMode(D1, OUTPUT);
  pinMode(D2, OUTPUT);
  Blynk.begin(auth, ssid, pass);
}

void loop() {
  Blynk.run();
}