Arduino Nano ESP32 - Button - Long Press Short Press
This tutorial provides instructions on how to use Arduino Nano ESP32 to detect the long press and short press, In detail, we will learn:
- How to detect the short press on the button
- How to detect the long press on the button
- How to detect both the long press and short press
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
This tutorial will use the internal pull-up resistor. The state of the button is HIGH when normal and LOW when pressed.
How To Detect Short Press
- Measure the time between the pressed and released events.
- If the duration is shorter than a pre-defined time, the short press event is detected.
Let's see step by step:
- Define how long the maximum of short press lasts
#define SHORT_PRESS_TIME 500 // 500 milliseconds
- Detect the button is pressed and save the pressed time
if(prev_state == HIGH && button_state == LOW)
pressed_time = millis();
- Detect the button is released and save the released time
if(prev_state == LOW && button_state == HIGH)
released_time = millis();
- Calculate press duration and
long press_duration = released_time - pressed_time;
- Determine the short press by comparing the press duration with the defined short press time.
if( press_duration < SHORT_PRESS_TIME )
Serial.println("A short press is detected");
Arduino Nano ESP32 Code for detecting the short press
/*
* 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-button-long-press-short-press
*/
#define BUTTON_PIN D2 // Arduino Nano ESP32 pin D2 pin connected to button
#define SHORT_PRESS_TIME 500 // 500 milliseconds
int prev_button_state = LOW; // The previous state from the input pin
int button_state; // The current reading from the input pin
unsigned long pressed_time = 0;
unsigned long released_time = 0;
void setup() {
Serial.begin(9600);
pinMode(BUTTON_PIN, INPUT_PULLUP);
}
void loop() {
// read the state of the switch/button:
button_state = digitalRead(BUTTON_PIN);
if (prev_button_state == HIGH && button_state == LOW) // button is pressed
pressed_time = millis();
else if (prev_button_state == LOW && button_state == HIGH) { // button is released
released_time = millis();
long press_duration = released_time - pressed_time;
if ( press_duration < SHORT_PRESS_TIME )
Serial.println("A short press is detected");
}
// save the the last state
prev_button_state = button_state;
}
Detailed Instructions
- If this is the first time you use Arduino Nano ESP32, see how to setup environment for Arduino Nano ESP32 on Arduino IDE.
- Upload the above code to Arduino Nano ESP32 via Arduino IDE
- Press the button shortly several times.
- Check out the result on the Serial Monitor. It looks like the below:
COM6
A short press is detected
Autoscroll
Clear output
9600 baud
Newline
※ NOTE THAT:
The Serial Monitor may print several short presses for a single press. This is a normal behavior of the button. This behavior is called the “chattering phenomenon”. We will learn how to eliminate this issue later in this tutorial.
How To Detect Long Press
There are two use cases for detecting the long press.
- The long-press event is detected right after the button is released
- The long-press event is detected while the button is being pressed.
In the first case:
- Measure the time duration between the pressed event and released event.
- If the duration is longer than a pre-defined time, the long-press event is detected.
In the second case: during the time the button is being pressed, do the below process repteatedly:
- Measure the pressing time.
- If the duration is longer than the pre-defined time, the long-press event is detected.
- Otherwise, repeat the process until the button is released
Arduino Nano ESP32 Code for detecting long press when released
/*
* 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-button-long-press-short-press
*/
#define BUTTON_PIN D2 // Arduino Nano ESP32 pin D2 pin connected to button
#define LONG_PRESS_TIME 1000 // 1000 milliseconds
int prev_button_state = LOW; // The previous state from the input pin
int button_state; // The current reading from the input pin
unsigned long pressed_time = 0;
unsigned long released_time = 0;
void setup() {
Serial.begin(9600);
pinMode(BUTTON_PIN, INPUT_PULLUP);
}
void loop() {
// read the state of the switch/button:
button_state = digitalRead(BUTTON_PIN);
if(prev_button_state == HIGH && button_state == LOW) // button is pressed
pressed_time = millis();
else if(prev_button_state == LOW && button_state == HIGH) { // button is released
released_time = millis();
long press_duration = released_time - pressed_time;
if( press_duration > LONG_PRESS_TIME )
Serial.println("A long press is detected");
}
// save the the last state
prev_button_state = button_state;
}
Detailed Instructions
- If this is the first time you use Arduino Nano ESP32, see how to setup environment for Arduino Nano ESP32 on Arduino IDE.
- Upload the above code to Arduino Nano ESP32 via Arduino IDE
- Press and release the button after one second.
- Check out the result on the Serial Monitor. It looks like the below:
COM6
A long press is detected
Autoscroll
Clear output
9600 baud
Newline
Arduino Nano ESP32 Code for detecting long press during pressing
/*
* 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-button-long-press-short-press
*/
#define BUTTON_PIN D2 // Arduino Nano ESP32 pin D2 pin connected to button
#define LONG_PRESS_TIME 1000 // 1000 milliseconds
int prev_button_state = LOW; // The previous state from the input pin
int button_state; // The current reading from the input pin
unsigned long pressed_time = 0;
bool is_pressing = false;
bool is_long_detected = false;
void setup() {
Serial.begin(9600);
pinMode(BUTTON_PIN, INPUT_PULLUP);
}
void loop() {
// read the state of the switch/button:
button_state = digitalRead(BUTTON_PIN);
if(prev_button_state == HIGH && button_state == LOW) { // button is pressed
pressed_time = millis();
is_pressing = true;
is_long_detected = false;
} else if(prev_button_state == LOW && button_state == HIGH) { // button is released
is_pressing = false;
}
if(is_pressing == true && is_long_detected == false) {
long press_duration = millis() - pressed_time;
if( press_duration > LONG_PRESS_TIME ) {
Serial.println("A long press is detected");
is_long_detected = true;
}
}
// save the the last state
prev_button_state = button_state;
}
Detailed Instructions
- If this is the first time you use Arduino Nano ESP32, see how to setup environment for Arduino Nano ESP32 on Arduino IDE.
- Upload the above code to Arduino Nano ESP32 via Arduino IDE
- Press and release the button after several seconds.
- Check out the result on the Serial Monitor. It looks like the below:
COM6
A long press is detected
Autoscroll
Clear output
9600 baud
Newline
How To Detect Both Long Press and Short Press
Short Press and Long Press after released
/*
* 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-button-long-press-short-press
*/
#define BUTTON_PIN D2 // Arduino Nano ESP32 pin D2 pin connected to button
#define SHORT_PRESS_TIME 1000 // 1000 milliseconds
#define LONG_PRESS_TIME 1000 // 1000 milliseconds
int prev_button_state = LOW; // The previous state from the input pin
int button_state; // The current reading from the input pin
unsigned long pressed_time = 0;
unsigned long released_time = 0;
void setup() {
Serial.begin(9600);
pinMode(BUTTON_PIN, INPUT_PULLUP);
}
void loop() {
// read the state of the switch/button:
button_state = digitalRead(BUTTON_PIN);
if (prev_button_state == HIGH && button_state == LOW) // button is pressed
pressed_time = millis();
else if (prev_button_state == LOW && button_state == HIGH) { // button is released
released_time = millis();
long press_duration = released_time - pressed_time;
if ( press_duration < SHORT_PRESS_TIME )
Serial.println("A short press is detected");
if ( press_duration > LONG_PRESS_TIME )
Serial.println("A long press is detected");
}
// save the the last state
prev_button_state = button_state;
}
Detailed Instructions
- If this is the first time you use Arduino Nano ESP32, see how to setup environment for Arduino Nano ESP32 on Arduino IDE.
- Upload the above code to Arduino Nano ESP32 via Arduino IDE
- Long and short press the button.
- Check out the result on the Serial Monitor. It looks like the below:
※ NOTE THAT:
The Serial Monitor may show several short press detection when long press. This is the normal behavior of the button. This behavior is called the “chattering phenomenon”. The issue will be solved in the last part of this tutorial.
Short Press and Long Press During pressing
/*
* 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-button-long-press-short-press
*/
#define BUTTON_PIN D2 // Arduino Nano ESP32 pin D2 pin connected to button
#define SHORT_PRESS_TIME 1000 // 1000 milliseconds
#define LONG_PRESS_TIME 1000 // 1000 milliseconds
int prev_button_state = LOW; // The previous state from the input pin
int button_state; // The current reading from the input pin
unsigned long pressed_time = 0;
unsigned long released_time = 0;
bool is_pressing = false;
bool is_long_detected = false;
void setup() {
Serial.begin(9600);
pinMode(BUTTON_PIN, INPUT_PULLUP);
}
void loop() {
// read the state of the switch/button:
button_state = digitalRead(BUTTON_PIN);
if (prev_button_state == HIGH && button_state == LOW) { // button is pressed
pressed_time = millis();
is_pressing = true;
is_long_detected = false;
} else if (prev_button_state == LOW && button_state == HIGH) { // button is released
is_pressing = false;
released_time = millis();
long press_duration = released_time - pressed_time;
if ( press_duration < SHORT_PRESS_TIME )
Serial.println("A short press is detected");
}
if (is_pressing == true && is_long_detected == false) {
long press_duration = millis() - pressed_time;
if ( press_duration > LONG_PRESS_TIME ) {
Serial.println("A long press is detected");
is_long_detected = true;
}
}
// save the the last state
prev_button_state = button_state;
}
Detailed Instructions
- If this is the first time you use Arduino Nano ESP32, see how to setup environment for Arduino Nano ESP32 on Arduino IDE.
- Upload the above code to Arduino Nano ESP32 via Arduino IDE
- Long and short press the button.
- Check out the result on the Serial Monitor. It looks like the below:
Long Press and Short Press with Debouncing
It is very important to debounce the button in many applications.
Debouncing is a little complicated, especially when using multiple buttons. To make it simple for newbies, we created a library, called ezButton.
We will use this library in below codes
Short Press and Long Press with debouncing after released
/*
* 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-button-long-press-short-press
*/
#include <ezButton.h>
#define SHORT_PRESS_TIME 1000 // 1000 milliseconds
#define LONG_PRESS_TIME 1000 // 1000 milliseconds
ezButton button(D2); // create ezButton object for pin Arduino Nano ESP32 pin D2
unsigned long pressed_time = 0;
unsigned long released_time = 0;
void setup() {
Serial.begin(9600);
button.setDebounceTime(50); // set debounce time to 50 milliseconds
}
void loop() {
button.loop(); // MUST call the loop() function first
if (button.isPressed())
pressed_time = millis();
if (button.isReleased()) {
released_time = millis();
long press_duration = released_time - pressed_time;
if ( press_duration < SHORT_PRESS_TIME )
Serial.println("A short press is detected");
if ( press_duration > LONG_PRESS_TIME )
Serial.println("A long press is detected");
}
}
Detailed Instructions
- If this is the first time you use Arduino Nano ESP32, see how to setup environment for Arduino Nano ESP32 on Arduino IDE.
- Install ezButton library. See How To
- Upload the above code to Arduino Nano ESP32 via Arduino IDE
- Long and short press the button.
- Check out the result on the Serial Monitor. It looks like the below:
Short Press and Long Press with debouncing During Pressing
/*
* 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-button-long-press-short-press
*/
#include <ezButton.h>
#define SHORT_PRESS_TIME 1000 // 1000 milliseconds
#define LONG_PRESS_TIME 1000 // 1000 milliseconds
ezButton button(D2); // create ezButton object for pin Arduino Nano ESP32 pin D2
unsigned long pressed_time = 0;
unsigned long released_time = 0;
bool is_pressing = false;
bool is_long_detected = false;
void setup() {
Serial.begin(9600);
button.setDebounceTime(50); // set debounce time to 50 milliseconds
}
void loop() {
button.loop(); // MUST call the loop() function first
if (button.isPressed()) {
pressed_time = millis();
is_pressing = true;
is_long_detected = false;
}
if (button.isReleased()) {
is_pressing = false;
released_time = millis();
long press_duration = released_time - pressed_time;
if ( press_duration < SHORT_PRESS_TIME )
Serial.println("A short press is detected");
}
if (is_pressing == true && is_long_detected == false) {
long press_duration = millis() - pressed_time;
if ( press_duration > LONG_PRESS_TIME ) {
Serial.println("A long press is detected");
is_long_detected = true;
}
}
}
Detailed Instructions
- If this is the first time you use Arduino Nano ESP32, see how to setup environment for Arduino Nano ESP32 on Arduino IDE.
- Install ezButton library. See How To
- Upload the above code to Arduino Nano ESP32 via Arduino IDE
- Long and short press the button.
- Check out the result on the Serial Monitor. It looks like the below:
Video Tutorial
Why Needs Long Press and Short Press
- To save the number of buttons and digital input pin. A single button can keep two or more functionalities. For example, short press for turning on the light, long press for turn on the fan.
- Use the long press instead the short press to avoid pressing by accident. For example, some kinds of devices use the button for factory reset. If the button is pressed by accident, it is dangerous.