IR Home Automation on DFRobot's Relay Shield

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Use DFRobots 4 Channel relay shield and control up to 4 appliances using just a infrared remote controller.

IR Home Automation on DFRobot's Relay Shield

Things used in this project


Hardware components

1 Arduino UNO Rev 3
1 DFRobot 4 Channel Relay Shield for Arduino
1 DFRobot IR Kit for Arduino

Software apps and online services


Arduino IDE



Everyone wants a remote to control all the appliances in your home. Some companies are introducing wireless controllers for various appliances but they are costly and you have to upgrade the existing for additional cost. So, what about making your own home automation system to control up to 4 appliances.




The Things you need


Hardware componens:

Arduino UNO Rev 34 Channel Relay shieldIR Kit for Arduino





4 Channel Relay Shield






Compatible with Arduino UNO Rev34 buttons to test moduleLED status indicator of relaySupport Xbee IO directly controlXbee socket for wireless communicationSelectable digital IO pin for control (Default digital 2,7,8,10)6 channels Analog IO & 13 channels Digital IOUp to 4 Relay with photo-coupled circuitContact Rating: 3A AC 120V / DC 24VMax Switching Voltage: AC 240V / DC 60V (Less than 38V is recommended)Max Switching Current: 5AMax Switching Power: AC 360VA / DC 90WElectrical Life (Min): 100,000 OperationsMechanical Life (Min): 10,000,000 OperationsSafety Standard (relay) UL cUL TUV CQCCoil Working Voltage 9VDCWorking temperature -30℃ to +85℃Working Humidity 40% - 85%Size: 95x65mm

IR Kit for Arduino







The Working


High Voltage VS Low Voltage


We all know that the appliances work on 110 V (USA) and 220 V (Asia) depending upon the region. But, the Arduino we are using is working on just 5 V. If we connect it directly to the mains supply to control the appliances just like controlling the LEDs, the board or the microcontroller will get burned. So, we use 5 V relay which works as an interface between the two voltage supplies. A signal is sent to relay by Arduino and relay switches on the circuit of the appliance.


Wireless Transmission of Data


We know that how will we switch the supply on but we need to send the signal from an IR remote to the receiver with Arduino. So, we can use any generic IR remote controller available in market. But, every remote controller comes with different codes for their buttons which they send it through IR LED. So, we need to find those codes for a random IR remote controller we are using.


For that, please click here for another project of mine on




Hook-up the Circuit


IR receiver and relay connections:


Just stack the relay shield on the Arduino board.On the shield, there are male headers for digital I/O pins.Connect the connector cable for IR module in the PIN 11 of the board. Keep in mind the colors on the wires matching with each other.




Testing it up!


Remember to install the IRremote.h library in the Arduino IDE. Download the ZIP File.


Upload the code attached in the end of project.Wait for the system to initialize.Now, press the POWER button to switch ON/OFF all the appliances.Press each corresponding button (like 1 for fan, 2 for light and so on) to switch ON/OFF them.






Try this and let me know in the comment section of your face any problem in the project I have published.



Schematics for the project



Relay connections to the appliance




The article was first published in hackster, September 17, 2017


author: Naman Chauhan

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