Arduino Nano ESP32 - Multiple Button
This tutorial instructs you how to program an Arduino Nano ESP32 to work with multiple buttons at the same time without using the delay() function. The tutorial offers code in two different ways:
- Handling multiple buttons with debounce on Arduino Nano ESP32.
- Managing multiple buttons with debounce using arrays on Arduino Nano ESP32.
We will use three buttons as examples. You can easily modify it to adapt for two buttons, four buttons, or even more.
Hardware Preparation
Or you can buy the following kits:
| 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 ESP32 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 ESP32 code was developed by newbiely.com
*
* This Arduino Nano ESP32 code is made available for public use without any restriction
*
* For comprehensive instructions and wiring diagrams, please visit:
* https://newbiely.com/tutorials/arduino-nano-esp32/arduino-nano-esp32-multiple-button
*/
#include <ezButton.h>
#define BUTTON_PIN_1 D4 // The Arduino Nano ESP32 pin connected to the button 1
#define BUTTON_PIN_2 D5 // The Arduino Nano ESP32 pin connected to the button 2
#define BUTTON_PIN_3 D6 // The Arduino Nano ESP32 pin connected to the button 3
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
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
}
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
// 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
/*
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);
*/
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");
}
Detailed Instructions
To get started with Arduino Nano ESP32, follow these steps:
- If you are new to Arduino Nano ESP32, refer to the tutorial on how to set up the environment for Arduino Nano ESP32 in the Arduino IDE.
- Wire the components according to the provided diagram.
- Connect the Arduino Nano ESP32 board to your computer using a USB cable.
- Launch the Arduino IDE on your computer.
- Select the Arduino Nano ESP32 board and its corresponding COM port.
- Do the wiring as above image.
- Connect the Arduino Nano ESP32 board to your PC via a USB cable
- Open Arduino IDE on your PC.
- Select the right Arduino Nano ESP32 board (e.g. Arduino Nano ESP32 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 ArduinoGetStarted
- Click Install button to install ezButton library.
- Copy the above code and paste it to Arduino IDE.
- Compile and upload code to Arduino Nano ESP32 board by clicking Upload button on Arduino IDE
- Open Serial Monitor on Arduino IDE
- Press and release the button one by one
8
Serial.println("Hello World!");
Message (Enter to send message to 'Arduino Nano ESP32' on 'COM15')
New Line
9600 baud
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