Arduino - Button - Relay

We are going to learn how to:

We will learn how to toggle relay each time button is pressed in Arduino - Button Toggles Relay tutorial.

By connecting relay to light bulb, led strip, motor or actuator... We can use the button to control light bulb, led strip, motor or actuator...

About Relay and Button

If you do not know about relay and button (pinout, how it works, how to program ...), learn about them in the following tutorials:

Wiring Diagram

Arduino Button Relay Wiring Diagram

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Arduino Code

/* * Created by * * This example code is in the public domain * * Tutorial page: */ const int BUTTON_PIN = 7; // Arduino pin connected to button's pin const int RELAY_PIN = 3; // Arduino pin connected to relay's pin void setup() { Serial.begin(9600); // initialize serial pinMode(BUTTON_PIN, INPUT_PULLUP); // set arduino pin to input pull-up mode pinMode(RELAY_PIN, OUTPUT); // set arduino pin to output mode } void loop() { int buttonState = digitalRead(BUTTON_PIN); // read new state if (buttonState == LOW) { Serial.println("The button is being pressed"); digitalWrite(RELAY_PIN, HIGH); // turn on } else if (buttonState == HIGH) { Serial.println("The button is unpressed"); digitalWrite(RELAY_PIN, LOW); // turn off } }

Quick Steps

  • Connect Arduino to PC via USB cable
  • Open Arduino IDE, select the right board and port
  • Copy the above code and open with Arduino IDE
  • Click Upload button on Arduino IDE to upload code to Arduino
Arduino IDE Upload Code
  • Press and keep pressing the button several seconds
  • See the change of relay's state

Code Explanation

Read the line-by-line explanation in comment lines of source code!

Video Tutorial

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Button and Relay on Commercial Products

Most electronic products have a reset button. Additionally, the button also keeps other functionalities in many products.

The Best Arduino Starter Kit