Gravity: Digital 5A Relay Module Example Code for Arduino

This article is a complete guide to controlling a relay using Arduino, featuring detailed instructions on setup, necessary hardware and software, a wiring diagram, and sample code to automate the relay's on/off function every two seconds.

Hardware Preparation

DFR0017 Digital 5A Relay Module (SKU:DFR0017 x 1)
DFRduino UNO R3 with IO Expansion Shield and USB Cable A-B (SKU:DFR0216-2 x 1)

Software Preparation

Development Tool: Arduino IDE (version unspecified). Download link: Arduino IDE

Wiring Diagram

wiring diagram

Other Preparation Work

Connect the relay module to Arduino according to the wiring diagram.
Ensure Arduino is powered and connected to your computer.

Sample Code

//Arduino Sample Code
//www.DFRobot.com
//Last modified on 14th March 2012 by HJS
//This code has been updated to work with the sample code provided in the Wiki

int Relay = 3;

void setup()
{
  pinMode(13, OUTPUT);         //Set Pin13 as output
  digitalWrite(13, HIGH);     //Set Pin13 High
  pinMode(Relay, OUTPUT);     //Set Pin3 as output
}
void loop()
{
          digitalWrite(Relay, HIGH);   //Turn on relay
          delay(2000);
          digitalWrite(Relay, LOW);    //Turn off relay
          delay(2000);
}

Result

Every two seconds, LED will be turned on and off.

Additional Information

The relay output state is indicated by a built-in LED for user convenience.

Example Code for Arduino-Relay On/Off Control