按键

类名: BtnA / BtnB / BtnC

read()

功能说明:

读取按键状态: 0,松开; 1,按下

函数原型:

uint8_t read()

案例程序:

#include <M5Core2.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());    //打印按键A按下的状态
}

lastChange()

功能说明:

返回最后一次状态发生变化的时间

函数原型:

uint32_t lastChange()

案例程序:

#include <M5Core2.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());    //打印按键A最后一次状态变化的时间
}

Press

isPressed()

功能说明:

返回按键按下状态: 如果按键按下,返回true; 否则返回false

函数原型:

uint8_t isPressed()

案例程序:

#include <M5Core2.h>

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

void loop() {
  M5.update();    //需添加M5.update()才能读取到按键的状态,细节请见System
  M5.Lcd.setCursor(0, 0);
  if (M5.BtnA.isPressed()) {    //如果按键按下
    M5.Lcd.println("Button is Pressed.");
  }else{
    M5.Lcd.println("Button is Released.");
  }
  delay(20);
}

pressedFor()

功能说明:

返回按键按下状态: 如果按键按下超过指定时间后,返回true; 否则返回false

函数原型:

uint8_t pressedFor(uint32_t ms)

案例程序:

#include <M5Core2.h>

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

void loop() {
  M5.update();
  if (M5.BtnA.pressedFor(2000)) {    //如果按键按下超过2秒
    M5.Lcd.println("Button A was pressed for more than 2 seconds.");
    delay(1000);
  }
}

wasPressed()

功能说明:

返回按键按下状态: 如果按键按下,只会返回一次true,否则返回false

函数原型:

uint8_t wasPressed()

案例程序:

#include <M5Core2.h>

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

void loop() {
  M5.update();
  if (M5.BtnA.wasPressed()) {    //如果按键按下
    M5.Lcd.println("Button is pressed.");
  } 
  delay(20);
}

Released

isReleased()

功能说明:

返回按键释放状态: 如果按键释放,返回true; 否则返回false

函数原型:

uint8_t isPressed()

案例程序:

#include <M5Core2.h>

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

void loop() {
  M5.update();    //需添加M5.update()才能读取到按键的状态,细节请见System
  if (M5.BtnA.isReleased()) {    //如果按键释放
    M5.Lcd.println("Button is released.");
  }else{
    M5.Lcd.println("Button is Pressed .");
  }
  delay(20);
}

releasedFor()

功能说明:

返回按键释放状态: 如果按键释放超过指定时间后,返回true; 否则返回false

函数原型:

uint8_t pressedFor(uint32_t ms)

案例程序:

#include <M5Core2.h>

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

void loop() {
  M5.update();
  M5.Lcd.setCursor(0, 0);
  if (M5.BtnA.releasedFor(2000)) {    //如果按键释放超过2秒
    M5.Lcd.println("Button A was released for more than 2 seconds.");
    delay(1000);
  }else{
    M5.Lcd.println("Button A is pressed                           ");
  }
}

wasReleased()

功能说明:

返回按键释放状态: 如果按键释放,只会返回一次true,否则返回false

函数原型:

uint8_t wasReleased()

案例程序:

#include <M5Core2.h>

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

void loop() {
  M5.update();
  if(M5.BtnA.wasReleased()) {    //如果按键释放
    M5.Lcd.println("Button is Released.");
  }
  delay(20);
}

wasReleasefor()

功能说明:

返回按键释放状态: 如果按键按下,在超过指定时间后释放,只会返回一次true,否则返回false

函数原型:

uint8_t wasReleasefor(uint32_t ms)

案例程序:

#include <M5Core2.h>

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

void loop() {
  M5.update();
  if (M5.BtnA.wasReleasefor(3000)) {    //如果按键A按下3s之后释放
      M5.Lcd.println("OK");
  }
}