在工程的main函数中如果加入：

 CAN1_Init();
接下来是创建LED的task和启动task；

 CAN1_Init函数具体如下：
void CAN1_Init()
{
    GPIO_InitTypeDef        GPIO_InitStructure;
    CAN_InitTypeDef     CAN_InitStructure;
    CAN_FilterInitTypeDef  CAN_FilterInitStructure;

   RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA,ENABLE);                                                                   
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_CAN1, ENABLE);            //使能CAN1时钟
 
    //引脚复用映射配置
    GPIO_PinAFConfig(GPIOA,GPIO_PinSource11,GPIO_AF_CAN1);          //GPIOA11复用为CAN1
    GPIO_PinAFConfig(GPIOA,GPIO_PinSource12,GPIO_AF_CAN1);          //GPIOA12复用为CAN1
 
    //初始化GPIO
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11| GPIO_Pin_12;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;                    //复用功能
    GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;                  //推挽输出
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;              //100MHz
    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;                    //上拉
    GPIO_Init(GPIOA, &GPIO_InitStructure);                          //初始化PA11,PA12
      
    //CAN单元设置
    CAN_InitStructure.CAN_TTCM=DISABLE;     
    CAN_InitStructure.CAN_ABOM=DISABLE; 
    CAN_InitStructure.CAN_AWUM=DISABLE;
    CAN_InitStructure.CAN_NART=ENABLE; 
    CAN_InitStructure.CAN_RFLM=DISABLE; 
    CAN_InitStructure.CAN_TXFP=DISABLE;
    CAN_InitStructure.CAN_Mode= CAN_Mode_Nomal;
    CAN_InitStructure.CAN_SJW=CAN_SJW_1tq;  
    CAN_InitStructure.CAN_BS1=CAN_BS1_3tq;
    CAN_InitStructure.CAN_BS2=CAN_BS2_1tq; 
    CAN_InitStructure.CAN_Prescaler=9;
    CAN_Init(CAN1, &CAN_InitStructure);                             //初始化CAN1
     
    //配置过滤器
    CAN_FilterInitStructure.CAN_FilterNumber  = 0;  
    CAN_FilterInitStructure.CAN_FilterMode  = CAN_FilterMode_IdList;
    CAN_FilterInitStructure.CAN_FilterScale  = CAN_FilterScale_32bit; 
    CAN_FilterInitStructure.CAN_FilterIdHigh  =0x0000    
    CAN_FilterInitStructure.CAN_FilterIdLow  = 0x0000;
    CAN_FilterInitStructure.CAN_FilterMaskIdHigh=0x0000;
    CAN_FilterInitStructure.CAN_FilterMaskIdLow = 0x0000;
    CAN_FilterInitStructure.CAN_FilterFIFOAssignment= CAN_Filter_FIFO0;
    CAN_FilterInitStructure.CAN_FilterActivation   = DISABLE; 
    CAN_FilterInit(&CAN_FilterInitStructure);  
}

在LED的task中
void led(void)
{
canTxMsg  msg1;

  msg1.ExtId =0x01234567;
msg1.IDE = CAN_Id_Extended;
msg1.DLC=0x01;
msg1.RTR =CAN_RTR_Data;
msg1.Data[0]=0x21;
while(1)
{
   LED0=~LED0;
   CAN_Transmit(CAN1,&msg1);
  OSTimeDlyHMSM(0,0,1,0,OS_OPT_TIME_HMSM_STRICT,&err);
}
}
CAN总线上无波形。PA12也无数据输出，LED闪烁，这是为什么呀？  把模式设置为环回模式，数据正常收到，PA12上依然无波形。

TX管脚映射到PH13上，在正常模式下 PH13 无波形，但是在环回模式下 PH13 出现了输出发送的波形