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。
1.先申请一个按键结构
struct Button button1;2.初始化按键对象，绑定按键的GPIO电平读取接口read_button_pin() ，后一个参数设置有效触发电平
button_init(&button1, read_button_pin, 0, 0);3.注册按键事件
button_attach(&button1, SINGLE_CLICK, Callback_SINGLE_CLICK_Handler);
button_attach(&button1, DOUBLE_CLICK, Callback_DOUBLE_Click_Handler);
...4.启动按键
button_start(&button1);5.设置一个5ms间隔的定时器循环调用后台处理函数
while(1) {
...
if(timer_ticks == 5) {
timer_ticks = 0;
button_ticks();
}
}MultiButton 使用C语言实现，基于面向对象方式设计思路，每个按键对象单独用一份数据结构管理：
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 button_id;
uint8_t (*hal_button_Level)(uint8_t button_id_);
BtnCallback cb[number_of_event];
struct Button* next;
};这样每个按键使用单向链表相连，依次进入 button_handler(struct Button* handle) 状态机处理，所以每个按键的状态彼此独立。
| 事件 | 说明 |
|---|---|
| PRESS_DOWN | 按键按下，每次按下都触发 |
| PRESS_UP | 按键弹起，每次松开都触发 |
| PRESS_REPEAT | 重复按下触发，变量repeat计数连击次数 |
| SINGLE_CLICK | 单击按键事件 |
| DOUBLE_CLICK | 双击按键事件 |
| LONG_PRESS_START | 达到长按时间阈值时触发一次 |
| LONG_PRESS_HOLD | 长按期间一直触发 |
#include "button.h"
unit8_t btn1_id = 0;
struct Button btn1;
uint8_t read_button_GPIO(uint8_t button_id)
{
// you can share the GPIO read function with multiple Buttons
switch(button_id)
{
case btn1_id:
return HAL_GPIO_ReadPin(B1_GPIO_Port, B1_Pin);
break;
default:
return 0;
break;
}
}
void BTN1_PRESS_DOWN_Handler(void* btn)
{
//do something...
}
void BTN1_PRESS_UP_Handler(void* btn)
{
//do something...
}
...
int main()
{
button_init(&btn1, read_button_GPIO, 0, btn1_id);
button_attach(&btn1, PRESS_DOWN, BTN1_PRESS_DOWN_Handler);
button_attach(&btn1, PRESS_UP, BTN1_PRESS_UP_Handler);
button_attach(&btn1, PRESS_REPEAT, BTN1_PRESS_REPEAT_Handler);
button_attach(&btn1, SINGLE_CLICK, BTN1_SINGLE_Click_Handler);
button_attach(&btn1, DOUBLE_CLICK, BTN1_DOUBLE_Click_Handler);
button_attach(&btn1, LONG_PRESS_START, BTN1_LONG_PRESS_START_Handler);
button_attach(&btn1, LONG_PRESS_HOLD, BTN1_LONG_PRESS_HOLD_Handler);
button_start(&btn1);
//make the timer invoking the button_ticks() interval 5ms.
//This function is implemented by yourself.
__timer_start(button_ticks, 0, 5);
while(1)
{}
}