【一起来玩RTOS系列】之RT-Thread 软件定时器-动态方法
定时器，是指从指定的时刻开始，经过一个指定时间，然后触发一个事件，类似定个时间提醒第二天能够按时起床。定时器有硬件定时器和软件定时器之分：硬件定时器是芯片本身提供的定时功能。一般是由外部晶振提供给芯片输入时钟，芯片向软件模块提供一组配置寄存器，接受控制输入，到达设定时间值后芯片中断控制器产生时钟中断。硬件定时器的精度一般很高，可以达到纳秒级别，并且是中断触发方式。
软件定时器是由操作系统提供的一类系统接口（函数），它构建在硬件定时器基础之上，使系统能够提供不受数目限制的定时器服务。
在操作系统中，通常软件定时器以系统节拍（tick）为单位。节拍长度指的是周期性硬件定时器两次中断间的间隔时间长度。这个周期性硬件定时器也称之为操作系统时钟。软件定时器以这个节拍时间长度为单位，数值必须是这个节拍的整数倍，例如节拍是10ms，那么上层软件定时器只能是10ms，20ms，100ms等，而不能取值为15ms。由于节拍定义了系统中定时器能够分辨的精确度，系统可以根据实际系统CPU的处理能力和实时性需求设置合适的数值，tick值设置越小，精度越高，但是系统开销也将越大（在1秒中系统用于处理时钟中断的次数 也就越多）。RT-Thread的定时器也基于类似的系统节拍，提供了基于节拍整数倍的定时能力。
RT-Thread的定时器提供两类定时器机制：第一类是单次触发定时器，这类定时器在启动后只会触发一次定时器事件，然后定时器自动停止。第二类是周期触发定时器，这类定时器会周期性的触发定时器事件，直到用户手动的停止定时器否则将永远持续执行下去。
使用动态API创建定时器示例如下：
/**
****************************************************
* File Name : main.c
* Description : Main program body
****************************************************
** This notice applies to any and all portions of this file
* that are not between comment pairs USER CODE BEGIN and
* USER CODE END. Other portions of this file, whether
* inserted by the user or by software development tools
* are owned by their respective copyright owners.
*
* COPYRIGHT(c) 2017 STMicroelectronics
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* 3. Neither the name of STMicroelectronics nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
****************************************************
*/
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "stm32f1xx_hal.h"
#include "usart.h"
#include "gpio.h"
/* USER CODE BEGIN Includes */
#include "rtthread.h"
/* USER CODE END Includes */
/* Private variables ---------------------------------------------------------*/
/* USER CODE BEGIN PV */
/* Private variables ---------------------------------------------------------*/
/* USER CODE END PV */
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
/* USER CODE BEGIN PFP */
/* Private function prototypes -----------------------------------------------*/
/* USER CODE END PFP */
/* USER CODE BEGIN 0 */
//重映射串口1到rt_kprintf
void rt_hw_console_output(const char *str)
{
/* empty console output */
char aa='\r';
rt_enter_critical();
while(*str!='\0')
{
if(*str=='\n')
{
HAL_UART_Transmit(&huart1, (uint8_t *)&aa, 1, 10);
}
HAL_UART_Transmit(&huart1, (uint8_t *)(str++), 1, 10);
}
rt_exit_critical();
}
//线程LED1
static void led1_thread_entry(void* parameter)
{
while(1)
{
LED1_Toggle();
rt_thread_delay(500); //延时
rt_kprintf("this is thread 1\r\n");
}
}
//线程LED2
static void led2_thread_entry(void* parameter)
{
while(1)
{
LED2_Toggle();
rt_thread_delay(100); //延时
rt_kprintf("this is thread 2\r\n");
}
}
/* 定时器的控制块 */
static rt_timer_t timer1;
static rt_timer_t timer2;
/* 定时器1超时函数 */
static void timeout1(void* parameter)
{
rt_kprintf("periodic timer is timeout\n");
LED3_Toggle();
}
/* 定时器2超时函数 */
static void timeout2(void* parameter)
{
rt_kprintf("one shot timer is timeout\n");
LED4_Toggle();
}
/* USER CODE END 0 */
int main(void)
{
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
/* MCU Configuration----------------------------------------------------------*/
///* Reset of all peripherals, Initializes the Flash interface and the Systick. */
//HAL_Init();
///* USER CODE BEGIN Init */
///* USER CODE END Init */
///* Configure the system clock */
//SystemClock_Config();
///* USER CODE BEGIN SysInit */
///* USER CODE END SysInit */
///* Initialize all configured peripherals */
//MX_GPIO_Init();
//MX_USART1_UART_Init();
/* USER CODE BEGIN 2 */
rt_thread_t tid1=RT_NULL;//线程句柄
rt_thread_t tid2=RT_NULL;//线程句柄
//创建动态线程
tid1=rt_thread_create("led1",//线程名字
led1_thread_entry,//线程入口函数
RT_NULL,//线程参数
256,//线程栈大小
3,//线程优先级
20);//线程时间片
//启动线程
rt_thread_startup(tid1);
//创建动态线程
tid2=rt_thread_create("led2",//线程名字
led2_thread_entry,//线程入口函数
RT_NULL,//线程参数
256,//线程栈大小
4,//线程优先级
20);//线程时间片
//启动线程
rt_thread_startup(tid2);
/* 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 */
1000, /* 定时长度，以OS Tick为单位，即1000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);
/* 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 */
5000, /* 定时长度为5000个OS Tick */
RT_TIMER_FLAG_ONE_SHOT); /* 单次定时器 */
/* 启动定时器 */
if (timer2 != RT_NULL) rt_timer_start(timer2);
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
//while (1)
//{
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
//
//}
/* USER CODE END 3 */
}
/** System Clock Configuration
*/
void SystemClock_Config(void)
{
RCC_OscInitTypeDef RCC_OscInitStruct;
RCC_ClkInitTypeDef RCC_ClkInitStruct;
/**Initializes the CPU, AHB and APB busses clocks
*/
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
RCC_OscInitStruct.HSEState = RCC_HSE_ON;
RCC_OscInitStruct.HSEPredivValue = RCC_HSE_PREDIV_DIV1;
RCC_OscInitStruct.HSIState = RCC_HSI_ON;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL9;
if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
{
_Error_Handler(__FILE__, __LINE__);
}
/**Initializes the CPU, AHB and APB busses clocks
*/
RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
|RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;
RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK)
{
_Error_Handler(__FILE__, __LINE__);
}
/**Configure the Systick interrupt time
*/
HAL_SYSTICK_Config(HAL_RCC_GetHCLKFreq()/1000);
/**Configure the Systick
*/
HAL_SYSTICK_CLKSourceConfig(SYSTICK_CLKSOURCE_HCLK);
/* SysTick_IRQn interrupt configuration */
HAL_NVIC_SetPriority(SysTick_IRQn, 0, 0);
}
/* USER CODE BEGIN 4 */
/* USER CODE END 4 */
/**
* @briefThis function is executed in case of error occurrence.
* @paramNone
* @retval None
*/
void _Error_Handler(char * file, int line)
{
/* USER CODE BEGIN Error_Handler_Debug */
/* User can add his own implementation to report the HAL error return state */
while(1)
{
}
/* USER CODE END Error_Handler_Debug */
}
#ifdef USE_FULL_ASSERT
/**
* @brief Reports the name of the source file and the source line number
* where the assert_param error has occurred.
* @param file: pointer to the source file name
* @param line: assert_param error line source number
* @retval None
*/
void assert_failed(uint8_t* file, uint32_t line)
{
/* USER CODE BEGIN 6 */
/* User can add his own implementation to report the file name and line number,
ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
/* USER CODE END 6 */
}
#endif
/**
* @}
*/
/**
* @}
*/
/**************** (C) COPYRIGHT STMicroelectronics ****END OF FILE***/
打开串口助手可以看到如下日志：
实验结果和预期一致：
源码下载：
请问做一个较长时间（几小时-几天）的定时功能也可以用这个方法吗？大神有空的话可以看下我发的提问帖，多谢！ Garfieldang 发表于 2017-11-19 16:34
请问做一个较长时间（几小时-几天）的定时功能也可以用这个方法吗？大神有空的话可以看下我发的提问帖，多 ...
时间较长建议用RTC；你使用一个变量，加定时器也是可以的，32位变量，1ms时基可以定时最长约50天 厉害了 定时插座是用这个方法实现的吗？ maomaodemao 发表于 2018-1-28 20:36
定时插座是用这个方法实现的吗？
不是
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