Introduction: Contact Less(Smart ) Room Controller

I teach 7th grade student. On behalf of my student Harsha and her brother im writing this instructable. In this COVID-19 situation we created a Smart Home Controller which I'm using now in my home, in which i have used IR sensor and made it Contact-less. This Room controller can be controlled using IR Sensors or we can even control using our Mobile(using Blynk App).

All step by step details are provided below.

Step 1: Required Parts

1)NodeMCU - 1 ( )

2)2-CH Relay Module- 1 ( )

3)IR Sensors - 2 ( )

4)Connectors -Few ( )

5)Hi-Link 12v or 5v Power Supply - 1 ( ) - 5v

6)7805 Voltage Regulator - 1 ( )

7)220uf capacitor - 1

8)22uf capacitor - 1

Step 2: Circuit Diagram

Connect all the components as per circuit diagram.

NodeMCU Relay Connections:

NodeMCU D0- Relay Signal pin 1(input pin)

NodeMCU D6- Relay Signal pin 2(input pin)

NodeMCU IR Sensors Connections:

NodeMCU D4- Sensor-1 Signal pin (output pin)

NodeMCU D5- Sensor-2 Signal pin (output pin)

All (NodeMCU ,Relay Module and Sensors) Vcc to 7805 Output pin(last pin)

All (NodeMCU ,Relay Module and Sensors)Gnd's to 7805 Gnd pin (middle pin)

Hi-Link Vo+ to 7805 Input pin (first pin) through capacitor +ve

Hi-Link Vo- to 7805 Gnd pin(middle pin) through capacitor -ve

Step 3: Arduino Code

Download the libraries from below links

WifiUdp ( )

ESP8266mDNS ( )

ArduinoOTA ( )

BlynkTimer ( )

thanks to techiesms for code reference.

Step 4: Blynk App Setup

Step1: Download Blynk App from playstore/appstore

Step2: Signup with your email id

Step3: Click on +New Project

Step4: Give your project a name

Step5: Select board to NodeMCU

Step6: Select Connection type to Wifi and click on submit

Step7: Verification code will be sent to your mail

Step8: Click on + button on top(android users) or click on screen(iphone users) and add a button to screen

Step9: Click on the button

Step10: Give your button a name

Step11: Select output to virutal pin v12 and slide from push to switch

Step12: Add another button and select output to virtual pin v13

Step13: Click on play button on top

Step 5: Add Wifi Credentials and Auth Code to Code

Step1: Copy the auth token form your mail and paste it in the code.

Step2: Give your wifi ssid in you code

Step3: Give your wifi password in your code

(reference in above pics)

Step 6: Upload

Step1: Connect your NodeMCU to your pc.

Step2: Open code in Arduino IDE and make necessary changes (auth token, ssid and password).

Step3: Click on tools and go to boards and select nodemcu1.0.

note: If you don't have nodemcu boards on your arduino ide please see this video (

Step4: Click on upload.

Step 7: Final Output

I have drilled holes in my switch board and kept all the circuit inside.

For Indication I've remover led's on relay board and added a 5 mm led and fixed in the switch board.


Feel free to ask me if you have any doubts in this instructable.

Thank you.

"Can't Touch This" Family Contest

Participated in the
"Can't Touch This" Family Contest