有什么足够体现操作系统优越性的按键检测方式

发布于 2023-12-15 00:27:07 浏览：397 订阅该版

如题，以下是我原来使用的，从逐飞科技那抄的，一个是信号量，一个是邮箱

```c
#define KEY_1   GET_PIN(C, 5)  // 定义主板上按键对应引脚
#define KEY_2   GET_PIN(A, 15)
#define KEY_3   GET_PIN(A, 0)
#define KEY_4   GET_PIN(A, 1)
//开关状态变量
rt_uint8_t key1_status = 1;
rt_uint8_t key2_status = 1;
rt_uint8_t key3_status = 1;
rt_uint8_t key4_status = 1;
//上一次开关状态变量
rt_uint8_t key1_last_status;
rt_uint8_t key2_last_status;
rt_uint8_t key3_last_status;
rt_uint8_t key4_last_status;
//开关信号量
static rt_sem_t key1_sem = RT_NULL;
static rt_sem_t key2_sem = RT_NULL;
static rt_sem_t key3_sem = RT_NULL;
static rt_sem_t key4_sem = RT_NULL;
rt_ubase_t keycode=0;
static void button_entry(void *parameter)
{
    //保存按键状态
    key1_last_status = key1_status;
    key2_last_status = key2_status;
    key3_last_status = key3_status;
    key4_last_status = key4_status;
    //读取当前按键状态
    key1_status = rt_pin_read(KEY_1);
    key2_status = rt_pin_read(KEY_2);
    key3_status = rt_pin_read(KEY_3);
    key4_status = rt_pin_read(KEY_4);
    //检测到按键按下之后并放开 释放一次信号量
    if(key1_status && !key1_last_status)
    {
        rt_sem_release(key1_sem);
        rt_mb_send(key_mailbox, KEY_1_ok);
    }
    if(key2_status && !key2_last_status)
    {
        rt_sem_release(key2_sem);
        rt_mb_send(key_mailbox, KEY_2_ok);
    }
    if(key3_status && !key3_last_status)
    {
        rt_sem_release(key3_sem);
        rt_mb_send(key_mailbox, KEY_3_ok);
    }
    if(key4_status && !key4_last_status)
    {
        rt_sem_release(key4_sem);
        rt_mb_send(key_mailbox, KEY_4_ok);
    }
}

rt_timer_t timer_button=RT_NULL;
rt_mailbox_t key_mailbox=RT_NULL;
int button_init(void)//按键初始化
{
    rt_pin_mode(KEY_1, PIN_MODE_INPUT_PULLUP );//上拉输入
    rt_pin_mode(KEY_2, PIN_MODE_INPUT_PULLUP );//上拉输入
    rt_pin_mode(KEY_3, PIN_MODE_INPUT_PULLDOWN );//下拉输入
    rt_pin_mode(KEY_4, PIN_MODE_INPUT_PULLUP );//上拉输入
    key1_sem = rt_sem_create("key1", 0, RT_IPC_FLAG_FIFO);  //创建按键的信号量，当按键按下就释放信号量，在需要使用按键的地方获取信号量即可
    key2_sem = rt_sem_create("key2", 0, RT_IPC_FLAG_FIFO);
    key3_sem = rt_sem_create("key3", 0, RT_IPC_FLAG_FIFO);
    key4_sem = rt_sem_create("key4", 0, RT_IPC_FLAG_FIFO);
    //创建邮箱
    key_mailbox = rt_mb_create("key_mb",5, RT_IPC_FLAG_FIFO);
    //创建线程
    timer_button = rt_timer_create("button", button_entry, RT_NULL, 50, RT_TIMER_FLAG_PERIODIC);

if(RT_NULL != timer_button)
    {
        rt_timer_start(timer_button);
    }
    return 0;
}

```