IoT Based Smart Home Controller Using NodeMCU ||

nodemcu ESP 12 development kit

Introduction : Smart Home Controller 

Ever thought of a life where you could just command your home appliances to work as you need just by using your voice? Gone are the days where you have to be a billionaire to have an automated house which is voice activated. In this short tutorial we are going to show you how you can control your electronic appliances like T.V, fans, lights etc over the internet with your voice and that to under a small  budget .

See alsoWhat is IoT ? – Simple Explanation of Meaning of Internet of Things

It involves the control and automation of lighting, heating (such as smart thermostats), ventilation, air conditioning (HVAC), and security, as well as home appliances such as washer/dryers/freezers. Wi-Fi is often used for remote monitoring and control.

A smart home controller (and/or software, and/or interface) is essential for remote access and control of your home automation devices (or peripherals) from a computer, smartphone or tablet.

Simply to control home appliances over the internet we are using NodeMCU ( Smart Home controller  ) and to connect NodeMCU with the home appliances we use a relay board.

Now to send on or off signals to the NodeMCU we use our smartphone, and we do this using the Blynk app. But we want to send the on or off signals using voice commands. To do this we use google assistant in our smartphone and an app called IFTTT.

See also: NodeMcu || WiFi Development Board for IoT

Selection of components:

  1.  Printed circuit board
  2.  Relay Board
  3.  Jumper Cables
  4.  NodeMCU
  5.  Step down transformer
  6.  Resistor
  7.  Capacitors
  8.  IC 7805
  9.  Diodes

Block Diagram: 


Circuit Diagram:

nodemcu ESP 12 development kit


  1. We will have to connect the NodeMCU with the Relay board, we can choose to do it with a bread board .
  2. Connect the D3 pin of NodeMCU with Pin 1 of Relay. Similarly connect D4 pin of NodeMCU with Relay pin 2, D5 with Relay 3 and D6 with Relay 4.
  3. Connect Ground Pin of Relay with Ground Pin of NodeMCU.
  4. Now to power up the NodeMCU you can use a normal phone charger, just make sure its voltage is not too high. And to power up the Relay board, you can use a battery or a separate breadboard power supplier.
  5. As we are using a four-channel relay we can connect at most 4 electronic appliances to the Relay and control them over the internet.
  6. Now if we want to connect our household appliances like Fan, Lights etc. which are connected to the main power of our house, we would recommend you take the help of a professional electrician and ask him/her to connect those appliances to the relay.

See also : Smart Meters :New way of measuring the consumption

Output Image :

Home controller using NodeMCU

Reference :

Read more about NodeMCU – here 


Sudhir Ohol & Ritesh Pawar :

They are Pursuing their graduation from D. Y. Patil Engineering College Pune. They are interested in Electronics and IoT . Love to develop new things.

IoTDunia is working towards a vision of empowering the youth by providing them with great professional opportunities with Internet of Things to build world class ecosystem.