Google Assistant, Blynk, IoT based Home Automation


In this IoT project, I have shown how to control home appliances from Google Assistant by connecting the Google Assistant with Blynk App using the IFTTT. With this IoT based project, we can control the relay module from the smartphone using Blynk or Google Assistant.

Google Assistant with Blynk App

How the project works:

  1. If you say any phase in the Google Assistant, then it will generate a trigger in IFTTT.
  2. IFTTT will send the signal to Blink Cloud server through Websockets
  3. Blynk will control the NodeMCU to turn on or turn off the respective relays

Related Project: Alexa Home Automation using NodeMCU.

Circuit for this IoT project

NodeMCU Relay module circuit 2

I have already explained how to control the relay module from Blynk App using NodeMCU in my previous project.

Please Click Here to visit my previous project on NodeMCU & Blynk to get the code and Blynk set up for this project.

Tutorial video for this project

In this tutorial video, I have explained the followings:
Blynk NodeMCU control Relay Circuit with GPIO pin details
Blynk app set up for this home automation project
Upload the Blynk example sketch from Arduino IDE
Connecting Google Assistant with Blynk using the IFTTT.

Connecting Blynk with Google Assistant

IFTTT platform

Here, I have used IFTTT to connect google assistant with Blynk.

Steps to connect Google Assistant with Blynk:

Google assistant configuration

Open IFTTT and search for Google Assistant and enter what do you want to say to control the relay module and the response from the google assistant.
Then click on Create Trigger.

Webhooks configuration for Blynk

After that search for Webhooks. Now, to generate the URL I need the IP of the Blynk-cloud. So to get the IP, I have to open the command prompt and type ping
URL structure: http://(Blynk-cloud IP)/(Auth Token)/update/D(GPIO pin)
Method : PUT
Content Type : Application/json
Body :
[“0”] –> To turn on the Relay (Active Low)
[“1”] –> To turn off the Relay (Active Low)

NodeMCU GPIO output pins
NodeMCU GPIO output pins

Then click on the Create action.

Applets of the IFTTT

Thus, I have created 4 applets to control 2-channel relay module from google assistant. You can create multiple applets as per the requirement.

Google Assistant control Relay:

Controlling relay with google assistant

As per the applets I have created on the IFTTT, if I say “Switch on Light” the relay-1 will turn on, and to turn off the relay-1, I have to say “Switch off Light“.

And to control the relay-2, I have to say “Switch on LED” or “Switch off LED”.

Blynk control Relay:

Controlling relay with Blynk

I can also control the relay module from Blynk App. So if I have internet in my smartphone, then I can control the relay module from anywhere in the world.

Click Here for more such IoT based Smart Home project.

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Please do share your feedback on this IoT based project. Thank you for your time.