FreeRTOS_软件定时器FreeRTOS 软件定时器实验创建2个任务，start_task、timercontrol_task。
start_stask：创建timercontrol_task任务；创建周期定时器AutoReloadTimer 和单次定时器OneShotTimer；创建⼆值信号量BinarySemaphore。
BinarySemaphore：接收串⼝命名，在中断中释放信号，在timercontrol_task中等待信号量，解析命名，通过不同的命令控制周期定时器AutoReloadTimer和单次定时器OneShotTimer的开启和关闭。
AutoReloadTimer 的回调函数会输出运⾏的次数OneShotTimer的回电函数会输出运⾏的次数任务分配：//任务优先级#define START_TASK_PRIO 1//任务堆栈⼤⼩#define START_STK_SIZE 128//任务句柄TaskHandle_t StartTask_Handler;//任务函数void start_task(void *pvParameters);//任务优先级#define TIMERCONTROL_TASK_PRIO 2//任务堆栈⼤⼩#define TIMERCONTROL_STK_SIZE 50//任务句柄TaskHandle_t TimerControlTask_Handler;//任务函数void timercontrol_task(void *pvParameters);SemaphoreHandle_t BinarySemaphore_Handle; // ⼆值信号量句柄TimerHandle_t AutoReloadTimer_Handle ; // 周期定时器句柄TimerHandle_t OneShotTimer_Handle; // 单次定时器句柄void AutoReloadTimerCallback(void); // 周期定时器回调函数void OneShotTimerCallback(void); // 周期定时器回调函数main() 函数int main(void){NVIC_PriorityGroupConfig(NVIC_PriorityGroup_4);//设置系统中断优先级分组4delay_init(); //延时函数初始化uart_init(115200); //初始化串⼝LED_Init(); //初始化LED//创建开始任务xTaskCreate((TaskFunction_t )start_task, //任务函数(const char* )"start_task", //任务名称(uint16_t )START_STK_SIZE, //任务堆栈⼤⼩(void* )NULL, //传递给任务函数的参数(UBaseType_t )START_TASK_PRIO, //任务优先级(TaskHandle_t* )&StartTask_Handler); //任务句柄vTaskStartScheduler(); //开启任务调度}命令解析相关函数：// 将字符串中的⼩写字母转换为⼤写// str：要转换的字符串// len：字符串长度void LowerToCap(u8 *str,u8 len){u8 i;for(i=0;i<len;i++){if((96<str[i])&&(str[i]<123)) // ⼩写字母str[i] = str[i]-32; // 转换为⼤写}}// 命令处理函数，将字符串命令转换成命令值// str：命令// 返回值：0xFF-命令错误其他值-命令值u8 CommandProcess(u8 *str){u8 CommandValue = 0xFF;if(strcmp((char*)str,"KEY1")==0) CommandValue = 1;else if(strcmp((char*)str,"KEY2")==0) CommandValue = 2;else if(strcmp((char*)str,"KEY3")==0) CommandValue = 3;else if(strcmp((char*)str,"KEY4")==0) CommandValue = 4;return CommandValue;}任务函数：//开始任务任务函数void start_task(void *pvParameters){taskENTER_CRITICAL(); //进⼊临界区// 创建⼆值信号量BinarySemaphore_Handle = xSemaphoreCreateBinary(); // 创建⼆值信号量if(BinarySemaphore_Handle ==NULL){printf("BinarySemaphore Create Failed!\r\n");}else{xSemaphoreGive(BinarySemaphore_Handle); // 释放信号量}// 创建周期定时器AutoReloadTimer_Handle = xTimerCreate( (const char *)"AutoReloadTimer", (TickType_t) 1000,(UBaseType_t) pdTRUE,(void *) 1,(TimerCallbackFunction_t)AutoReloadTimerCallback );if(AutoReloadTimer_Handle == NULL){printf("AutoReloadTimer Created Failed \r\n");}else{printf("AutoReloadTimer Created Success \r\n");}// 创建单次定时器OneShotTimer_Handle = xTimerCreate( (const char *)"OneShotTimer",(TickType_t) 2000,(UBaseType_t) pdFALSE,(void *) 2,(TimerCallbackFunction_t)OneShotTimerCallback );if(OneShotTimer_Handle == NULL){printf("OneShotTimer Created Failed \r\n");}else{printf("OneShotTimer Created Success \r\n");}//创建TIMECONTRFOL任务xTaskCreate((TaskFunction_t )timercontrol_task,(const char* )"timercontrol_task",(uint16_t )TIMERCONTROL_STK_SIZE,(void* )NULL,(UBaseType_t )TIMERCONTROL_TASK_PRIO,(TaskHandle_t* )&TimerControlTask_Handler);vTaskDelete(StartTask_Handler); //删除开始任务taskEXIT_CRITICAL(); //退出临界区}//TIMERCONTROL任务函数void timercontrol_task(void *pvParameters){u8 len = 0;u8 CommandValue = 0xFF;u8 CommandStr[USART_REC_LEN];BaseType_t err;while(1){xSemaphoreTake( BinarySemaphore_Handle, portMAX_DELAY ); // 死等len = USART_RX_STA&0x3fff; // 得到此次接收到的数据长度 sprintf((char *)CommandStr,"%s",USART_RX_BUF); // 装载数据CommandStr[len] = '\0'; // 加上字符串结尾符号LowerToCap(CommandStr,len); // 将字符串转换为⼤写CommandValue = CommandProcess(CommandStr); // 命令解析if(CommandValue != 0xFF) // 接收到正确的命令{switch(CommandValue){case1: // 开启周期定时器err = xTimerStart( AutoReloadTimer_Handle, 0 );if(err == pdFAIL){printf("AutoReloadTimer Start Failed! \r\n");}else{printf("AutoReloadTimer Start Succeed! \r\n");}break;case2: // 关闭周期定时器err = xTimerStop( AutoReloadTimer_Handle, 0 );if(err == pdFAIL){printf("AutoReloadTimer Stop Failed! \r\n");}else{printf("AutoReloadTimer Stop Succeed! \r\n");}break;case3: // 开启单次定时器err = xTimerStart( OneShotTimer_Handle, 0 );if(err == pdFAIL){printf("OneShotTimer Start Failed! \r\n");}else{printf("OneShotTimer Start Succeed! \r\n");}break;case4: // 关闭周期定时器err = xTimerStop( OneShotTimer_Handle, 0 );if(err == pdFAIL){printf("OneShotTimer Stop Failed! \r\n");}else{printf("OneShotTimer Stop Succeed! \r\n");}break;}}else{printf("Cmd error!\r\n");}USART_RX_STA = 0;}}定时器回调函数：// 周期定时器回调函数void AutoReloadTimerCallback(void){static u8 count = 0;count ++;printf("AutoReloadTimerCallback running %d timers\r\n",count);}// 周期定时器回调函数void OneShotTimerCallback(void){static u8 count = 0;count ++;printf("OneShotTimerCallback running %d timers\r\n",count);}串⼝中断初始化和中断处理函数u8 USART_RX_BUF[USART_REC_LEN]; //接收缓冲,最⼤USART_REC_LEN个字节.//接收状态//bit15，接收完成标志//bit14，接收到0x0d//bit13~0，接收到的有效字节数⽬u16 USART_RX_STA=0; //接收状态标记void uart_init(u32 bound){//GPIO端⼝设置GPIO_InitTypeDef GPIO_InitStructure;USART_InitTypeDef USART_InitStructure;NVIC_InitTypeDef NVIC_InitStructure;RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1|RCC_APB2Periph_GPIOA, ENABLE); //使能USART1，GPIOA时钟 //USART1_TX GPIOA.9GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9; //PA.9GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //复⽤推挽输出GPIO_Init(GPIOA, &GPIO_InitStructure);//初始化GPIOA.9//USART1_RX GPIOA.10初始化GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;//PA10GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;//浮空输⼊GPIO_Init(GPIOA, &GPIO_InitStructure);//初始化GPIOA.10//Usart1 NVIC 配置NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=8 ;//抢占优先级3NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0; //⼦优先级3NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ通道使能NVIC_Init(&NVIC_InitStructure); //根据指定的参数初始化VIC寄存器//USART 初始化设置USART_ART_BaudRate = bound;//串⼝波特率USART_ART_WordLength = USART_WordLength_8b;//字长为8位数据格式USART_ART_StopBits = USART_StopBits_1;//⼀个停⽌位USART_ART_Parity = USART_Parity_No;//⽆奇偶校验位USART_ART_HardwareFlowControl = USART_HardwareFlowControl_None;//⽆硬件数据流控制USART_ART_Mode = USART_Mode_Rx | USART_Mode_Tx; //收发模式USART_Init(USART1, &USART_InitStructure); //初始化串⼝1USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);//开启串⼝接受中断USART_Cmd(USART1, ENABLE); //使能串⼝1}extern SemaphoreHandle_t BinarySemaphore_Handle; // ⼆值信号量句柄void USART1_IRQHandler(void) //串⼝1中断服务程序{u8 Res;BaseType_t xHigherPriorityTaskWoken = pdFALSE;if(USART_GetITStatus(USART1, USART_IT_RXNE) != RESET) //接收中断(接收到的数据必须是0x0d 0x0a结尾) {Res =USART_ReceiveData(USART1); //读取接收到的数据if((USART_RX_STA&0x8000)==0)//接收未完成{if(USART_RX_STA&0x4000)//接收到了0x0d{if(Res!=0x0a)USART_RX_STA=0;//接收错误,重新开始else USART_RX_STA|=0x8000; //接收完成了}else//还没收到0X0D{if(Res==0x0d)USART_RX_STA|=0x4000;else{USART_RX_BUF[USART_RX_STA&0X3FFF]=Res ;USART_RX_STA++;if(USART_RX_STA>(USART_REC_LEN-1))USART_RX_STA=0;//接收数据错误,重新开始接收}}}}if((BinarySemaphore_Handle != NULL) && (USART_RX_STA&0x8000)){xSemaphoreGiveFromISR( BinarySemaphore_Handle, &xHigherPriorityTaskWoken ); // 释放互斥信号量 portYIELD_FROM_ISR(xHigherPriorityTaskWoken); // 如果需要进⾏⼀次任务切换}}#define USART_REC_LEN 20 //定义最⼤接收字节数 200#define EN_USART1_RX 1 //使能（1）/禁⽌（0）串⼝1接收extern u8 USART_RX_BUF[USART_REC_LEN]; //接收缓冲,最⼤USART_REC_LEN个字节.末字节为换⾏符注意：串⼝中断的优先级在FreeRTOS的优先级管理范围内。
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