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Project 4: Switch a LED on when Switch is Closed (Button)

Created on: 2 August 2012

Tutorial 10 – Pages

A switch (push button) is connected to the Arduino. When the switch is closed, the LED switches on, when the switch is opened, the LED switches off.

Similar to the DigitalReadSerial project (project 2), but instead of sending the state of the switch to the serial monitor, the state of the switch is displayed on an LED. The Arduino on-board LED is used so no external LED is necessary.

Parts Needed

  • 1 × 10k resistor (1/4W, 5%)
  • 1 × push button or toggle switch (or just a wire link will do)

Arduino Website Page


In the Arduino IDE

File → Examples → 2.Digital → Button

Building the Circuit

Connect the switch to the Arduino as done in project 2 (DigitalReadSerial), or see the connection diagram for the Button project on the Arduino website.

Programming and Operating the Circuit

In the Arduino IDE, select File → Examples → 2.Digital → Button to open the Button sketch. Verify and upload the sketch.

Closing the switch that is connected to Arduino pin 2 will switch the on-board "L" LED on the Arduino board on. Opening the switch will switch the LED off again.

Project 4 Video

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