天津做网页设计的公司青岛关键词推广seo

一、简介

二、实验

//创建一个单次定时器和一个周期定时器，打开两个定时器然后等待10s关闭定时器，此时会发现单次定时器打印1次停止，周期定时器打印5次停止
#include "FreeRTOS_demo.h"#define START_TASK_PRIO         1
#define START_TASK_STACK_SIZE   128
TaskHandle_t    start_task_handler;
void start_task( void * pvParameters );/* TASK1 任务 配置* 包括: 任务句柄 任务优先级 堆栈大小 创建任务*/
#define TASK1_PRIO         2
#define TASK1_STACK_SIZE   128
TaskHandle_t    task1_handler;
void task1( void * pvParameters );void timer1_callback( TimerHandle_t pxTimer );
void timer2_callback( TimerHandle_t pxTimer );void freertos_demo(void)
{    xTaskCreate((TaskFunction_t         )   start_task,(char *                 )   "start_task",(configSTACK_DEPTH_TYPE )   START_TASK_STACK_SIZE,(void *                 )   NULL,(UBaseType_t            )   START_TASK_PRIO,(TaskHandle_t *         )   &start_task_handler );vTaskStartScheduler();
}TimerHandle_t timer1_handle = 0;    /* 单次定时器 */
TimerHandle_t timer2_handle = 0;    /* 周期定时器 */void start_task( void * pvParameters )
{taskENTER_CRITICAL();               /* 进入临界区 *//* 单次定时器 */timer1_handle = xTimerCreate( "timer1", 500,pdFALSE,(void *)1,timer1_callback );/* 周期定时器 */timer2_handle = xTimerCreate( "timer2", 2000,pdTRUE,(void *)2,timer2_callback );xTaskCreate((TaskFunction_t         )   task1,(char *                 )   "task1",(configSTACK_DEPTH_TYPE )   TASK1_STACK_SIZE,(void *                 )   NULL,(UBaseType_t            )   TASK1_PRIO,(TaskHandle_t *         )   &task1_handler );vTaskDelete(NULL);taskEXIT_CRITICAL();                /* 退出临界区 */
}/* 任务一，按键扫描并控制软件定时器 */
void task1( void * pvParameters )
{uint8_t key = 0;xTimerStart(timer1_handle,portMAX_DELAY);xTimerStart(timer2_handle,portMAX_DELAY);vTaskDelay(10000);xTimerStop(timer1_handle,portMAX_DELAY);xTimerStop(timer2_handle,portMAX_DELAY);while(1) {}
}/* timer1的超时回调函数 */
void timer1_callback( TimerHandle_t pxTimer )
{static uint32_t timer = 0;printf("timer1的运行次数：%d\r\n",++timer);
}/* timer2的超时回调函数 */
void timer2_callback( TimerHandle_t pxTimer )
{static uint32_t timer = 0;printf("timer2的运行次数：%d\r\n",++timer);
}