ART
BEAUTY & WELLNESS
CRAFT
CULTURE & HISTORY
ENTERTAINMENT
ENVIRONMENT
FOOD & DRINKS
GREEN FUTURE
REVERSE ENGINEERING
SCIENCES
SPORTS
TECHNOLOGY
WEARABLES
Push Buttons — SIK Circuit 5
Ed

Created by

Ed

17. March 2026FI
74
0
0
0
0

Push Buttons — SIK Circuit 5

Use two push buttons for digital input. Learn about digitalRead(), pull-up resistors, and boolean logic (AND, OR, NOT) to control an LED.

Instructions

1

Parts & Introduction

Push buttons are the simplest digital input. This experiment uses two buttons with an XOR logic gate: the LED turns on if you press either button, but turns off if you press both. You'll learn about digitalRead(), pull-up resistors, and boolean logic.

Parts Needed

  • 1x Arduino Uno + USB cable
  • 1x Breadboard
  • 2x Push Buttons
  • 1x LED (any color)
  • 1x 330Ω Resistor
  • 2x 10KΩ Resistors (pull-ups)
  • 7x Jumper Wires

Materials for this step:

SparkFun Inventors Kit - V3.2SparkFun Inventors Kit - V3.21 kit
Arduino Uno R31 piece
Breadboard1 piece
Push ButtonPush Button2 pieces
5mm LED1 piece
330 Ohm Resistor330 Ohm Resistor1 piece
10K Ohm Resistor10K Ohm Resistor2 pieces
Jumper WiresJumper Wires7 pieces

Tools needed:

Computer with Arduino IDE
2

Hardware Hookup

Wiring Instructions

  1. Place both push buttons across the center canyon of the breadboard.
  2. Button 1: Connect one pin to GND. Connect the opposite diagonal pin to Arduino Digital Pin 2. Add a 10K resistor between Pin 2 and 5V (pull-up).
  3. Button 2: Connect one pin to GND. Connect the opposite diagonal pin to Arduino Digital Pin 3. Add a 10K resistor between Pin 3 and 5V (pull-up).
  4. Connect LED positive leg to Digital Pin 13, negative leg through 330Ω resistor to GND.

Note: The pull-up resistors hold the input HIGH when the button is not pressed. Pressing the button connects the pin to GND (LOW).

Materials for this step:

Push ButtonPush Button2 pieces
5mm LED1 piece
330 Ohm Resistor330 Ohm Resistor1 piece
10K Ohm Resistor10K Ohm Resistor2 pieces
Breadboard1 piece
Jumper WiresJumper Wires7 pieces
3

Arduino Code

Open the Arduino IDE and upload the following sketch to your Arduino board.

push_buttons.inoarduino
/*
SparkFun Inventor's Kit
Example sketch 05 — PUSH BUTTONS

Use pushbuttons for digital input.
LED on if pressing button 1 OR button 2, but not both (XOR).

Hardware connections:
  Button 1: one pin to GND, diagonal pin to digital pin 2
            10K pullup resistor between pin 2 and 5V
  Button 2: one pin to GND, diagonal pin to digital pin 3
            10K pullup resistor between pin 3 and 5V
  LED: positive to pin 13, negative through 330 ohm to GND

This code is completely free for any use.
*/

const int button1Pin = 2;
const int button2Pin = 3;
const int ledPin = 13;

void setup()
{
  pinMode(button1Pin, INPUT);
  pinMode(button2Pin, INPUT);
  pinMode(ledPin, OUTPUT);
}

void loop()
{
  int button1State, button2State;

  button1State = digitalRead(button1Pin);
  button2State = digitalRead(button2Pin);

  // XOR logic: on if either pressed, off if both pressed
  if (((button1State == LOW) || (button2State == LOW))
      && !
      ((button1State == LOW) && (button2State == LOW)))
  {
    digitalWrite(ledPin, HIGH);
  }
  else
  {
    digitalWrite(ledPin, LOW);
  }
}

Materials for this step:

Arduino Uno R31 piece

Tools needed:

Computer with Arduino IDE
4

Test & Experiment

What You Should See

The LED turns on when you press either button individually. It turns off when you press both buttons simultaneously (XOR logic).

Troubleshooting

  • Not responding: Push buttons are square — it's easy to put them in the wrong orientation. Try rotating 90°.
  • LED always on or always off: Check the pull-up resistor connections. Without them, the input pin floats and reads random values.

Experiments to Try

  • Change the logic to AND (both buttons required) or simple OR.
  • Use the buttons to control an RGB LED — one button for color, one for brightness.
  • Try using INPUT_PULLUP mode to eliminate the external resistors.

Materials

8

Tools Required

1
  • 13
    Computer with Arduino IDE
Estimated Total
$153.00

Related blueprints

Other builds that share materials, tools, or techniques with this one.

Using an LCD — SIK Circuit 15electronics1 shared material
Simon Says — SIK Circuit 16electronics1 shared material
Using a Piezo Buzzer — SIK Circuit 11electronics1 shared material
Sewing a LilyPad LED Circuitelectronics
Sewing a LilyPad Button Circuitelectronics
Building an Ultrasonic Parking Sensorelectronics

CC0 Public Domain

This blueprint is released under CC0. You are free to copy, modify, distribute, and use this work for any purpose, without asking permission.

Support the Maker by purchasing products through their Blueprint where they earn a Maker Commission set by Vendors, or create a new iteration of this Blueprint and include it as a connection in your own Blueprint to share revenue.

Discussion

(0)

Log in to join the discussion

Loading comments...