Arduino Nano - Multiple Button
This tutorial instructs you how to program an Arduino Nano so that it can handle multiple buttons at the same time without relying on the delay() function. The tutorial offers code in two different ways:
- Arduino Nano code for handling multiple buttons with debounce.
- Arduino Nano code for handling multiple buttons with debounce using arrays.
We will use foir buttons as examples. You can easily modify it to adapt for two buttons, three buttons, five buttons, or even more.
Hardware Preparation
Or you can buy the following sensor kits:
| 1 | × | DIYables Sensor Kit (30 sensors/displays) | |
| 1 | × | DIYables Sensor Kit (18 sensors/displays) |
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Wiring Diagram
This image is created using Fritzing. Click to enlarge image
Arduino Nano Code - Multiple Buttons with debounce
When using multiple buttons, things can get complicated in certain scenarios:
- Applications requiring button debouncing (see why we need to debounce for buttons)
- Applications needing to detect state changes (pressed/released)
Thankfully, the ezButton library streamlines this process by internally managing debounce and button events. This relieves users from the task of managing timestamps and variables when utilizing the library. Additionally, employing an array of buttons can enhance code clarity and brevity.
/*
* This Arduino Nano code was developed by newbiely.com
*
* This Arduino Nano code is made available for public use without any restriction
*
* For comprehensive instructions and wiring diagrams, please visit:
* https://newbiely.com/tutorials/arduino-nano/arduino-nano-multiple-button
*/
#include <ezButton.h>
#define BUTTON_PIN_1 4 // The Arduino Nano pin connected to the button 1
#define BUTTON_PIN_2 5 // The Arduino Nano pin connected to the button 2
#define BUTTON_PIN_3 6 // The Arduino Nano pin connected to the button 3
#define BUTTON_PIN_4 7 // The Arduino Nano pin connected to the button 4
ezButton button1(BUTTON_PIN_1); // create ezButton object for button 1
ezButton button2(BUTTON_PIN_2); // create ezButton object for button 2
ezButton button3(BUTTON_PIN_3); // create ezButton object for button 3
ezButton button4(BUTTON_PIN_4); // create ezButton object for button 4
void setup() {
Serial.begin(9600);
button1.setDebounceTime(100); // set debounce time to 100 milliseconds
button2.setDebounceTime(100); // set debounce time to 100 milliseconds
button3.setDebounceTime(100); // set debounce time to 100 milliseconds
button4.setDebounceTime(100); // set debounce time to 100 milliseconds
}
void loop() {
button1.loop(); // MUST call the loop() function first
button2.loop(); // MUST call the loop() function first
button3.loop(); // MUST call the loop() function first
button4.loop(); // MUST call the loop() function first
// get button state after debounce
int button1_state = button1.getState(); // the state after debounce
int button2_state = button2.getState(); // the state after debounce
int button3_state = button3.getState(); // the state after debounce
int button4_state = button4.getState(); // the state after debounce
/*
Serial.print("The button 1 state: ");
Serial.println(button1_state);
Serial.print("The button 2 state: ");
Serial.println(button2_state);
Serial.print("The button 3 state: ");
Serial.println(button3_state);
Serial.print("The button 4 state: ");
Serial.println(button4_state);
*/
if (button1.isPressed())
Serial.println("The button 1 is pressed");
if (button1.isReleased())
Serial.println("The button 1 is released");
if (button2.isPressed())
Serial.println("The button 2 is pressed");
if (button2.isReleased())
Serial.println("The button 2 is released");
if (button3.isPressed())
Serial.println("The button 3 is pressed");
if (button3.isReleased())
Serial.println("The button 3 is released");
if (button4.isPressed())
Serial.println("The button 4 is pressed");
if (button4.isReleased())
Serial.println("The button 4 is released");
}
Detailed Instructions
- Do the wiring as above image.
- Connect the Arduino Nano board to your PC via a USB cable
- Open Arduino IDE on your PC.
- Select the right Arduino Nano board (e.g. Arduino Nano Uno) and COM port.
- Click to the Libraries icon on the left bar of the Arduino IDE.
- Search “ezButton”, then find the button library by Arduino NanoGetStarted
- Click Install button to install ezButton library.
- Copy the above code and paste it to Arduino IDE.
- Compile and upload code to Arduino Nano board by clicking Upload button on Arduino IDE
- Open Serial Monitor on Arduino IDE
- Press and release the button one by one
COM6
The button 1 is pressed
The button 1 is released
The button 2 is pressed
The button 2 is released
The button 3 is pressed
The button 3 is released
The button 4 is pressed
The button 4 is released
Autoscroll
Clear output
9600 baud
Newline