Button

• Button
  • read
  • lastChange
  • isPressed
  • wasPressed
  • pressedFor
  • isReleased
  • releasedFor
  • wasReleased
  • wasReleasefor

read

函数原型:

uint8_t read();

功能说明:

• 读取按键状态

传入参数:

• null

返回值:

• uint8_t:
  • 1:按下
  • 0:释放

案例程序:

#include <M5Stack.h>

void setup() {
  M5.begin();
  M5.Lcd.println("Please pressed Button A.");
}

void loop() {
  M5.Lcd.setCursor(0, 0);
  M5.Lcd.printf("Button A Status: %d ",M5.BtnA.read());
}

lastChange

函数原型:

uint32_t lastChange();

功能说明:

• 获取上一次状态更新的时间

传入参数:

• null

返回值:

• uint32_t: 上一次状态更新的时间ms

案例程序:

#include <M5Stack.h>

void setup() {
  M5.begin();
  M5.Lcd.println("Please pressed Button A.");
}

void loop() {
  M5.update();
  M5.Lcd.setCursor(0, 0);
  M5.Lcd.printf("The last change at %d ms /n",M5.BtnA.lastChange());
}

isPressed

函数原型:

uint8_t isPressed();

功能说明:

• 判断按键是否按下

传入参数:

• null

返回值:

• uint8_t:
  • 1: 按键处于按下状态
  • 0: 按键不处于按下状态

案例程序:

#include <M5Stack.h>

void setup() {
  M5.begin();
  M5.Lcd.println("Please pressed Button A.");
}

void loop() {
  M5.update();
  M5.Lcd.setCursor(0, 0);
  if (M5.BtnA.isPressed()) {
    M5.Lcd.println("Button is Pressed.");
  }else{
    M5.Lcd.println("Button is Released.");
  }
  delay(20);
}

wasPressed

函数原型:

uint8_t wasPressed();

功能说明:

• 判断按键由释放状态, 变化为按下状态

传入参数:

• null

返回值:

• uint8_t:
  • 1: 触发按键由释放状态变化为按下状态
  • 0: 未触发按键由释放状态变化为按下状态

案例程序:

#include <M5Stack.h>

void setup() {
  M5.begin();
  M5.Lcd.println("Please pressed Button A.");
}

void loop() {
  M5.update();
  if (M5.BtnA.wasPressed()) {    
    M5.Lcd.println("Button is pressed.");
  } 
  delay(20);
}

pressedFor

函数原型:

uint8_t pressedFor(uint32_t ms);

功能说明:

• 判断按键是否按下超过指定超时时间

传入参数:

• uint32_t ms：
  • 按键按下超时时间ms

返回值:

• uint8_t:
  • 1: 触发按键释放超过超时时间
  • 0: 未触发

案例程序:

#include <M5Stack.h>

void setup() {
  M5.begin();
  M5.Lcd.println("Please pressed Button A.");
}

void loop() {
  M5.update();
  if (M5.BtnA.pressedFor(2000)) {
    M5.Lcd.println("Button A was pressed for more than 2 seconds.");
    delay(1000);
  }
}

isReleased

函数原型:

uint8_t isPressed();

功能说明:

• 判断按键是否处于释放状态

传入参数:

• null

返回值:

• uint8_t:
  • 1: 按键处于释放状态
  • 0: 按键不处于释放状态

案例程序:

#include <M5Stack.h>

void setup() {
  M5.begin();
}

void loop() {
  M5.update();
  if (M5.BtnA.isReleased()) {
    M5.Lcd.println("Button is released.");
  }else{
    M5.Lcd.println("Button is Pressed .");
  }
  delay(20);
}

releasedFor

函数原型:

uint8_t pressedFor(uint32_t ms);

功能说明:

• 判断按键释放超时时间

传入参数:

• uint32_t ms：
  • 按键释放超时时间ms

返回值:

• uint8_t:
  • 1: 触发按键释放超过超时时间
  • 0: 未触发

案例程序:

#include <M5Stack.h>

void setup() {
  M5.begin();
}

void loop() {
  M5.update();
  M5.Lcd.setCursor(0, 0);
  if (M5.BtnA.releasedFor(2000)) {
    M5.Lcd.println("Button A was released for more than 2 seconds.");
    delay(1000);
  }else{
    M5.Lcd.println("Button A is pressed                           ");
  }
}

wasReleased

函数原型:

uint8_t wasReleased();

功能说明:

• 判断按键由按下状态, 变化为释放状态

传入参数:

• null

返回值:

• uint8_t:
  • 1: 触发按键由按下状态变化为释放状态
  • 0: 未触发按键由按下状态变化为释放状态

案例程序:

#include <M5Stack.h>

void setup() {
  M5.begin();
  M5.Lcd.println("Please pressed Button A.");
}

void loop() {
  M5.update();
  if(M5.BtnA.wasReleased()) {
    M5.Lcd.println("Button is Released.");
  }
  delay(20);
}

wasReleasefor

函数原型:

uint8_t wasReleasefor(uint32_t ms);

功能说明:

• 判断按键是否按下超过指定超时时间, 释放后触发

传入参数:

• uint32_t ms：
  • 按键释放超时时间ms

返回值:

• uint8_t:
  • 1: 触发按键释放超过超时时间
  • 0: 未触发

案例程序:

#include <M5Stack.h>

void setup() {
  M5.begin();
  M5.Lcd.println("Please pressed Button A.");
}

void loop() {
  M5.update();
  if (M5.BtnA.wasReleasefor(3000)) {
      M5.Lcd.println("OK");
  }
}