优雅的按键模块-----Multi-button

优雅的按键模块-----Multi-button

​ 在我们日常开发和使用的过程中常常使用了一些按键,利用按键实现不同的功能,比如长按,短按,双击等等。但是每次都是采用标志等等来实现信息的读取,是否有一个优雅的方式来使用按键呢?答案是有的。

## Multi-button

​

​ 作者的简介是：

MultiButton 是一个小巧简单易用的事件驱动型按键驱动模块，可无限量扩展按键，按键事件的回调异步处理方式可以简化你的程序结构，去除冗余的按键处理硬编码，让你的按键业务逻辑更清晰。

首先来看看头Mul-Button的数据结构

typedef enum {
	PRESS_DOWN = 0,
	PRESS_UP,
	PRESS_REPEAT,
	SINGLE_CLICK,
	DOUBLE_CLICK,
	LONG_PRESS_START,
	LONG_PRESS_HOLD,
	number_of_event,
	NONE_PRESS
}PressEvent;

typedef struct Button {
	uint16_t ticks;
	uint8_t  repeat : 4;
	uint8_t  event : 4;
	uint8_t  state : 3;
	uint8_t  debounce_cnt : 3;
	uint8_t  active_level : 1;
	uint8_t  button_level : 1;
	uint8_t  (*hal_button_Level)(void);
	BtnCallback  cb[number_of_event];
	struct Button* next;
}Button;

第一个是枚举类型,像按键按下的类型的枚举

• PRESS_DOWN

按下

• PRESS_UP

按下后弹起

• PRESS_REPEAT

重复按

• SINGLE_CLICK

单击

• DOUBLE_CLICK

双击

• LONG_PRESS_START

长按到一定阈值触发

• LONG_PRESS_HOLD

长按期间一直触发

第二个是按键对下结构体的定义,解释其中重要的

button_level:有效电平

(*hal_button_Level)(void):按键读取函数

BtnCallback cb:按键对应事件的回调函数

大家有没有注意到

	uint8_t  repeat : 4;
	uint8_t  event : 4;
	uint8_t  state : 3;
	uint8_t  debounce_cnt : 3;
	uint8_t  active_level : 1;
	uint8_t  button_level : 1;

这个“:”是结构体中的位域,因为有些后面的数字代表着占据了多少的bit,这个有机会在以后来讲,总之是一个节省内存的方式

接下来看看几个开放出来比较重要的API

/*初始化Button的结构体*/
void button_init(struct Button* handle, uint8_t(*pin_level)(), uint8_t active_level);
/*结构体和对应事件以及其回调函数的绑定*/
void button_attach(struct Button* handle, PressEvent event, BtnCallback cb);
/*开启按键*/
int  button_start(struct Button* handle);
/*按键的时钟*/
void button_ticks(void);

具体的用法如下

首先先创建Button对象

/*
    申请三个按键对象
*/
struct Button Button_Up;
struct Button Button_OK;
struct Button Button_Down;

为Button添加时基

/*我这里选择STM32上的定时器11*/
void TIM1_TRG_COM_TIM11_IRQHandler(void)
{
  /* USER CODE BEGIN TIM1_TRG_COM_TIM11_IRQn 0 */

  /* USER CODE END TIM1_TRG_COM_TIM11_IRQn 0 */
  HAL_TIM_IRQHandler(&htim11);
  /* USER CODE BEGIN TIM1_TRG_COM_TIM11_IRQn 1 */
    button_ticks();
    HAL_TIM_Base_Start_IT(&htim11);
  /* USER CODE END TIM1_TRG_COM_TIM11_IRQn 1 */
}

为Button创建读取电平的函数,设置其有效电平,并启动对象

/*设置读取电平的函数*/
uint8_t read_button_up()
{
    return HAL_GPIO_ReadPin(Button_Up_GPIO_Port,Button_Up_Pin);
}
uint8_t read_button_ok()
{
    return HAL_GPIO_ReadPin(Button_OK_GPIO_Port,Button_OK_Pin);
}
uint8_t read_button_down()
{
    return HAL_GPIO_ReadPin(Button_Down_GPIO_Port,Button_Down_Pin);
}
/*初始化三个对象,并为其绑定读取函数*/
  button_init(&Button_Up, read_button_up, 0);
  button_init(&Button_OK, read_button_ok, 0);
  button_init(&Button_Down, read_button_down, 0);
/*将对象添加到Button链表*/
  button_start(&Button_OK);
  button_start(&Button_Up);
  button_start(&Button_Down);

为对象的对应事件及其对应时间的函数来绑定

/*为了方便,我这里只举例其中Button_OK*/
/*长按事件触发的函数*/
static void Button_ok_long_press_callback(void *btn)
{
    /*将当前页的退出标志位置1*/
    Page[Page_Tim_ID].Exit_flag = true;
}
/*绑定到Button_OK的长按事件*/
button_attach(&Button_OK, LONG_PRESS_START, Button_ok_long_press_callback);

然后就可以,效果也是非常的好

其中有几个重要参数在头文件里可以根据自己的情况来修改

#define TICKS_INTERVAL    1	//这个是时基的间隔,单位是ms#define SHORT_TICKS       (50 /TICKS_INTERVAL)//这个是短按的阈值时间#define LONG_TICKS        (500 /TICKS_INTERVAL)//这个是长按的阈值时间

至此multi-Button模块就到这里结束,接下重要的是他的设计思路

int button_start(struct Button* handle){	struct Button* target = head_handle;	while(target) {		if(target == handle) return -1;	//already exist.		target = target->next;	}	handle->next = head_handle;	head_handle = handle;	return 0;}

这个是开启Button的函数,显然是采用链表的形式,每次开启对象都将对象加入链表

void button_ticks(){	struct Button* target;	for(target=head_handle; target; target=target->next) {		button_handler(target);	}}

这个是开启button_ticks()的时基函数,每次触发遍历这个Button的链表,然后去将每个对象传入button_handler()

void button_handler(struct Button* handle){	uint8_t read_gpio_level = handle->hal_button_Level();	//ticks counter working..	if((handle->state) > 0) handle->ticks++;	/*------------button debounce handle---------------*/	if(read_gpio_level != handle->button_level) { //not equal to prev one		//continue read 3 times same new level change		if(++(handle->debounce_cnt) >= DEBOUNCE_TICKS) {			handle->button_level = read_gpio_level;			handle->debounce_cnt = 0;		}	} else { //leved not change ,counter reset.		handle->debounce_cnt = 0;	}	/*-----------------State machine-------------------*/	switch (handle->state) {	case 0:		if(handle->button_level == handle->active_level) {	//start press down			handle->event = (uint8_t)PRESS_DOWN;			EVENT_CB(PRESS_DOWN);			handle->ticks = 0;			handle->repeat = 1;			handle->state = 1;		} else {			handle->event = (uint8_t)NONE_PRESS;		}		break;	case 1:		if(handle->button_level != handle->active_level) { //released press up			handle->event = (uint8_t)PRESS_UP;			EVENT_CB(PRESS_UP);			handle->ticks = 0;			handle->state = 2;		} else if(handle->ticks > LONG_TICKS) {			handle->event = (uint8_t)LONG_PRESS_START;			EVENT_CB(LONG_PRESS_START);			handle->state = 5;		}		break;	case 2:		if(handle->button_level == handle->active_level) { //press down again			handle->event = (uint8_t)PRESS_DOWN;			EVENT_CB(PRESS_DOWN);			handle->repeat++;			EVENT_CB(PRESS_REPEAT); // repeat hit			handle->ticks = 0;			handle->state = 3;		} else if(handle->ticks > SHORT_TICKS) { //released timeout			if(handle->repeat == 1) {				handle->event = (uint8_t)SINGLE_CLICK;				EVENT_CB(SINGLE_CLICK);			} else if(handle->repeat == 2) {				handle->event = (uint8_t)DOUBLE_CLICK;				EVENT_CB(DOUBLE_CLICK); // repeat hit			}			handle->state = 0;		}		break;	case 3:		if(handle->button_level != handle->active_level) { //released press up			handle->event = (uint8_t)PRESS_UP;			EVENT_CB(PRESS_UP);			if(handle->ticks < SHORT_TICKS) {				handle->ticks = 0;				handle->state = 2; //repeat press			} else {				handle->state = 0;			}		}else if(handle->ticks > SHORT_TICKS){ // long press up			handle->state = 0;		}		break;	case 5:		if(handle->button_level == handle->active_level) {			//continue hold trigger			handle->event = (uint8_t)LONG_PRESS_HOLD;			EVENT_CB(LONG_PRESS_HOLD);		} else { //releasd			handle->event = (uint8_t)PRESS_UP;			EVENT_CB(PRESS_UP);			handle->state = 0; //reset		}		break;	}}

这个则是对传入对象进行对应事件的判断,并且触发对应的事件回调函数,设计的整体式一个状态机的思想,有兴趣的可以自己去看看

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开源地址

https://github.com/0x1abin/MultiButton