软件定时器
FreeRTOS提供了现成的软件定时器功能，可以一定程度上替代硬件定时器，但精度不高。
实验：创建一个任务，两个定时器，按键开启定时器，一个500ms打印一次，一个1000ms打印一次。
实现：在【STM32】FreeRTOS事件组学习基础上修改。
/* USER CODE END Variables */osThreadId Task1Handle;osTimerId myTimer01Handle;osTimerId myTimer02Handle; /* Create the timer(s) *//* definition and creation of myTimer01 */osTimerDef(myTimer01, Callback01);myTimer01Handle = osTimerCreate(osTimer(myTimer01), osTimerPeriodic, NULL);/* definition and creation of myTimer02 */osTimerDef(myTimer02, Callback02);myTimer02Handle = osTimerCreate(osTimer(myTimer02), osTimerPeriodic, NULL);/* USER CODE BEGIN RTOS_TIMERS */上面的代码是CubeMX封装好的。
下面编写自己需要的任务代码。
第一步：修改记数周期
/* start timers, add new ones, ... */xTimerChangePeriod(myTimer01Handle,500,200);xTimerChangePeriod(myTimer02Handle,1000,200);第二步：按键任务
void StartDefaultTask(void const * argument){/* USER CODE BEGIN StartDefaultTask *//* Infinite loop */for(;;){if(HAL_GPIO_ReadPin(GPIOE,GPIO_PIN_2)==0){osDelay(20);if(HAL_GPIO_ReadPin(GPIOE,GPIO_PIN_2)==0){printf("KEY1\r\n");xTimerStart(myTimer01Handle,100);xTimerStart(myTimer02Handle,100);osDelay(200);}}if(HAL_GPIO_ReadPin(GPIOE,GPIO_PIN_2)==0){osDelay(20);if(HAL_GPIO_ReadPin(GPIOE,GPIO_PIN_2)==0){printf("KEY2\r\n");xTimerStop(myTimer01Handle,100);xTimerStop(myTimer02Handle,100);osDelay(200);}}}/* USER CODE END StartDefaultTask */}第三步：定时器回调
void Callback01(void const * argument){/* USER CODE BEGIN Callback01 */printf("Timer1\r\n");/* USER CODE END Callback01 */}/* Callback02 function */void Callback02(void const * argument){/* USER CODE BEGIN Callback02 */printf("Timer2\r\n");/* USER CODE END Callback02 */}
