RT-Thread-15天rt-thread入门学习 - 第十四天（软件定时器）RT-Thread问答社区

15天rt-thread入门学习 - 第十四天（软件定时器）

发布于 2018-05-30 14:52:46 浏览：2211 订阅该版

软件定时器，主要包括：
1、使用软件定时器需要的配置宏
   #define RT_USING_TIMER_SOFT
2、例程源码解读及软件定时器相关操作介绍
   使用硬件定时器需要做的工作：
   需要设置定时周期  启动/停止  写中断处理函数
   ---------------------------------------------------------------
   使用软件定时器需要做的工作：
   定义静态定时器对象：
   static struct rt_timer_t timer_s;
   定义动态定时器对象：
   static rt_timer_t timer1;
   ---------------------------------------------------------------
   初始化/创建
   result = rt_timer_init(timer_s,
                                    "timer_s",
				    timerout_s,
				   RT_NULL,
				  10,
				   RT_TIMER_FLAG_PERIODIC);
   timer1 = rt_timer_creat("timer1",                /* 定时器名字是 timer1 */
                           timeout1,                /* 超时时回调的处理函数 */
                           RT_NULL,                 /* 超时函数的入口参数 */
                           10,                      /* 定时长度，以OS Tick为单位，即10个OS Tick */
                           RT_TIMER_FLAG_PERIODIC); /* 周期性定时器 */
   #define RT_TIMER_FLAG_DEACTIVATED 0x0 /* 定时器为非激活态*/
   #define RT_TIMER_FLAG_ACTIVATED 0x1   /* 定时器为激活状态*/
   #define RT_TIMER_FLAG_ONE_SHOT 0x0    /* 单次定时*/
   #define RT_TIMER_FLAG_PERIODIC 0x2    /* 周期定时*/
   #define RT_TIMER_FLAG_HARD_TIMER 0x0  /* 硬件定时器*/
   #define RT_TIMER_FLAG_SOFT_TIMER 0x4  /* 软件定时器*/
   ----------------------------------------------------------------
   启动/停止
   rt_timer_start(timer1);
   rt_timer_stop(timer1);
   ----------------------------------------------------------------
   超时处理函数
   static void timeout1(void *parameter);
   ----------------------------------------------------------------
   控制
   rt_timer_control(timer1, RT_TIMER_CTRL_SET_ONESHOT, (void *)&timeout);
   #define RT_TIMER_CTRL_SET_TIME 0x0     /* 设置定时器超时时间*/
   #define RT_TIMER_CTRL_GET_TIME 0x1     /* 获得定时器超时时间*/
   #define RT_TIMER_CTRL_SET_ONESHOT 0x2  /* 设置定时器为单一超时型*/
   #define RT_TIMER_CTRL_SET_PERIODIC 0x3 /* 设置定时器为周期型定时器*/
   ----------------------------------------------------------------
   脱离/删除
   rt_timer_detach(timer1);
   rt_timer_delete(timer1);
   
3、软件定时器使用的两个注意点
   a 定时器设定的时间必须是OS tick的整数倍
   b RT-Thread的定时器与其他实时操作系统的定时器实现稍微有些不同（特别是RT-Thread早期版本的实现中），因为RT-Thread里定时器默认的方式是HARD_TIMER定时器，即定时器超时后，超时函数是在系统时钟中断的上下文环境中运行的。在中断上下文中的执行方式决定了定时器的超时函数不应该调用任何会让当前上下文挂起的系统函数；也不能够执行非常长的时间，否则会导致其他中断的响应时间加长或抢占了其他线程执行的时间。

作业：
1、使用控制函数修改定时器的超时时间
-------------------------------------------------------------------------------------
在示例基础上修改后的程序：
```#include <rtthread.h>

/* 定时器的控制块 */
static rt_timer_t timer1;
static rt_timer_t timer2;
static int cnt = 0;
static int cntTimer2 = 0;

/* 定时器1超时函数 */
static void timeout1(void *parameter)
{
    rt_tick_t timeout = 30;

rt_kprintf("periodic timer is timeout ");
 
 cnt++;
 rt_kprintf("timer1 count : %d ", cnt);

/* 运行10次 */
 if (cnt == 10)
 {
 //rt_timer_control(timer1, RT_TIMER_CTRL_SET_ONESHOT, (void *)&timeout);
 rt_timer_control(timer1,RT_TIMER_CTRL_SET_TIME,(void *)&timeout);
 rt_kprintf("Timeout of timer1 is %d ticks. ",timeout);
 }
 else if(cnt >= 15)
 {
 rt_timer_control(timer1, RT_TIMER_CTRL_SET_ONESHOT, (void *)&timeout);
 rt_kprintf("Time1 is stoped. ",timeout);
 rt_timer_control(timer2, RT_TIMER_CTRL_SET_ONESHOT, (void *)&timeout);
 rt_kprintf("Time2 is stoped. ",timeout);
 }
}

/* 定时器2超时函数 */
static void timeout2(void *parameter)
{
 cntTimer2++;
 rt_kprintf("timer2 count : %d ", cntTimer2);
}

int timer_sample_init(void)
{
    /* 创建定时器1 */
    timer1 = rt_timer_create("timer1", /* 定时器名字是 timer1 */
                             timeout1, /* 超时时回调的处理函数 */
                             RT_NULL, /* 超时函数的入口参数 */
                             10, /* 定时长度，以OS Tick为单位，即10个OS Tick */
                             RT_TIMER_FLAG_PERIODIC); /* 周期性定时器 */

/* 启动定时器 */
 if (timer1 != RT_NULL)
 {
 rt_timer_start(timer1);
 rt_kprintf("Timeout of timer1 is 10 ticks. ");
 }

/* 创建定时器2 */
    timer2 = rt_timer_create("timer2", /* 定时器名字是 timer2 */
                             timeout2, /* 超时时回调的处理函数 */
                             RT_NULL, /* 超时函数的入口参数 */
                             10, /* 定时长度为10个OS Tick */
                             RT_TIMER_FLAG_PERIODIC); /* 单次定时器 */

/* 启动定时器 */
 if (timer2 != RT_NULL)
 {
 rt_timer_start(timer2);
 rt_kprintf("Timeout of timer2 is 10 ticks. ");
 }
 return 0;
}
/* 如果设置了RT_SAMPLES_AUTORUN，则加入到初始化线程中自动运行 */
#if defined (RT_SAMPLES_AUTORUN) && defined(RT_USING_COMPONENTS_INIT)
 INIT_APP_EXPORT(timer_sample_init);
#endif
/* 导出到 msh 命令列表中 */
MSH_CMD_EXPORT(timer_sample_init, timer sample);```
-------------------------------------------------------------------------------------
运行结果：
``` \ | /
- RT - Thread Operating System
 / | \ 3.0.4 build May 30 2018
 2006 - 2018 Copyright by rt-thread team
msh >timer
timer_sample_init
msh >timer_sample_init
Timeout of timer1 is 10 ticks.
Timeout of timer2 is 10 ticks.
msh >periodic timer is timeout
timer1 count : 1
timer2 count : 1
periodic timer is timeout
timer1 count : 2
timer2 count : 2
periodic timer is timeout
timer1 count : 3
timer2 count : 3
periodic timer is timeout
timer1 count : 4
timer2 count : 4
periodic timer is timeout
timer1 count : 5
timer2 count : 5
periodic timer is timeout
timer1 count : 6
timer2 count : 6
periodic timer is timeout
timer1 count : 7
timer2 count : 7
periodic timer is timeout
timer1 count : 8
timer2 count : 8
periodic timer is timeout
timer1 count : 9
timer2 count : 9
periodic timer is timeout
timer1 count : 10
Timeout of timer1 is 30 ticks.
timer2 count : 10
timer2 count : 11
timer2 count : 12
periodic timer is timeout
timer1 count : 11
timer2 count : 13
timer2 count : 14
timer2 count : 15
periodic timer is timeout
timer1 count : 12
timer2 count : 16
timer2 count : 17
timer2 count : 18
periodic timer is timeout
timer1 count : 13
timer2 count : 19
timer2 count : 20
timer2 count : 21
periodic timer is timeout
timer1 count : 14
timer2 count : 22
timer2 count : 23
timer2 count : 24
periodic timer is timeout
timer1 count : 15
Time1 is stoped.
Time2 is stoped.
timer2 count : 25
```