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Using relay switch with Arduino

ArudAndRelaySwitchHeaderImage.png

The article discusses how to operate a relay switch using an Arduino Uno.

Disclaimer

This post does not delve into the operation of relay switches.

Working sample

Before we continue, let's see what our final result will look like.

Items needed

- Arduino Uno

- 5V Relay switch

- Small DC motor

- 5 V DC power supply

Pre-requisites

This post assumes you already have,

1.     Arduino Editor installed on your laptop.​

2.    Your laptop connected to Arduino using the USB cable.

3.    Basic familiarity with Arduino programming using C++.

Technical details

How relay switch works?

This post does not delve into the operation of relay switches. There are plenty of resources available on the internet that cover this topic extensively.

RelayTrans.png
Schematic & Wiring diagrams
Schematic_IoT_2022-09-29.png
This is how the final setup looks like:
ArudRelaySwitch_completeSetup.jpg
How-to steps

Step 1: Connecting Arduino to relay switch

ArudRelaySwitch_ArduinoToRelay.jpg

Step 2: Connecting power supply to motor through relay switch

ArudRelaySwitch_RelaySwitch.jpg
ArudRelaySwitch_Relay_1.jpg
Step 3: Arduino C++ code

No additional libraries need to be downloaded. The code is straightforward.

C++ code

const int relayActivationPin = 9;

 

void setup() {  

      Serial.begin(9600);   //added by hari  

      pinMode(relayActivationPin, OUTPUT);

}

 

void loop() {  

      int counter = 0;  

      while (counter < 5){    

            counter++;    

            delay(3000);    

            Serial.print("RelayActivated...");    

            digitalWrite(relayActivationPin, HIGH);    

            delay(3000);    

            Serial.println("...and deactivated.");    

            digitalWrite(relayActivationPin, LOW);  

      }

}

Step 4: Testing the relay switch

Now that the setup should be ready, running the C++ code should activate the DC motor for a few seconds and then stop. This cycle should repeat continuously.

Closing note

I hope this post provides you with the essential details for connecting an Arduino with a relay switch to activate or deactivate a DC motor. For a demonstration, please refer to the accompanying video found at the top of this page.

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