STM32F072CBT6，调试CAN，换回模式收发都没有问题，但是接上USBCAN分析仪后，MCU给电脑发送，电脑上的的软件收不到数据；电脑...

flytent

各位大神，我用的STM32F072CBT6，调试CAN，换回模式收发都没有问题，但是接上USBCAN分析仪后，MCU给电脑发送，电脑上的的软件收不到数据；电脑软件给MCU发送，USBCAN的error灯亮，MCU收不到数据。哪位大神调过F072的CAN，指教一下！！！
  GPIO_InitTypeDef  GPIO_InitStructure;
  NVIC_InitTypeDef  NVIC_InitStructure;
  CAN_InitTypeDef  CAN_InitStructure;
  CAN_FilterInitTypeDef  CAN_FilterInitStructure;
  uint32_t i = 0;
  uint8_t TransmitMailbox = 0;

  /* NVIC configuration *******************************************************/
  /* Enable CAN RX0 interrupt IRQ channel */
  NVIC_InitStructure.NVIC_IRQChannel = CEC_CAN_IRQn;
  NVIC_InitStructure.NVIC_IRQChannelPriority = 0x0;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);

  /* CAN GPIOs configuration **************************************************/

  /* Enable GPIO clock */
  RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);

  /* Connect CAN pins to AF4 */
  GPIO_PinAFConfig(GPIOA, GPIO_PinSource11, GPIO_AF_4);
  GPIO_PinAFConfig(GPIOA, GPIO_PinSource12, GPIO_AF_4);

  /* Configure CAN RX and TX pins */
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11 |GPIO_Pin_12;//
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
  GPIO_InitStructure.GPIO_PuPd  = GPIO_PuPd_UP;
  GPIO_Init(GPIOA, &GPIO_InitStructure);

//  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11;// | GPIO_Pin_12
//  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;
////  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
//  GPIO_InitStructure.GPIO_OType = GPIO_OType_OD;
//  GPIO_InitStructure.GPIO_PuPd  = GPIO_PuPd_UP;
//  GPIO_Init(GPIOA, &GPIO_InitStructure);

  /* CAN configuration ********************************************************/  
  /* Enable CAN clock */
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_CAN, ENABLE);

  /* CAN register init */
  CAN_DeInit(CAN);
  CAN_StructInit(&CAN_InitStructure);

  /* CAN cell init */
  CAN_InitStructure.CAN_TTCM = DISABLE;
  CAN_InitStructure.CAN_ABOM = DISABLE;
  CAN_InitStructure.CAN_AWUM = DISABLE;
  CAN_InitStructure.CAN_NART = DISABLE;
  CAN_InitStructure.CAN_RFLM = DISABLE;
  CAN_InitStructure.CAN_TXFP = DISABLE;
  CAN_InitStructure.CAN_Mode = CAN_Mode_LoopBack;//CAN_Mode_Normal
  CAN_InitStructure.CAN_SJW = CAN_SJW_1tq;

  /* CAN Baudrate = 1MBps (CAN clocked at 36 MHz) */
  CAN_InitStructure.CAN_BS1 = CAN_BS1_9tq;//CAN_BS1_9tq
  CAN_InitStructure.CAN_BS2 = CAN_BS2_8tq;//CAN_BS2_8tq
  CAN_InitStructure.CAN_Prescaler = 4;//2
  //  CAN_Baud_Process(500,&CAN_InitStructure);
  CAN_Init(CAN, &CAN_InitStructure);

  /* CAN filter init "FIFO0" */
  CAN_FilterInitStructure.CAN_FilterNumber = 0;
  CAN_FilterInitStructure.CAN_FilterMode = CAN_FilterMode_IdMask;
  CAN_FilterInitStructure.CAN_FilterScale = CAN_FilterScale_32bit;
  CAN_FilterInitStructure.CAN_FilterIdHigh = 0;//0x6420
  CAN_FilterInitStructure.CAN_FilterIdLow = 0;//0x2461
  CAN_FilterInitStructure.CAN_FilterMaskIdHigh = 0x0000;
  CAN_FilterInitStructure.CAN_FilterMaskIdLow = 0x0000;
  CAN_FilterInitStructure.CAN_FilterFIFOAssignment = 0;
  CAN_FilterInitStructure.CAN_FilterActivation = ENABLE;
  CAN_FilterInit(&CAN_FilterInitStructure);

  /* CAN FIFO0 message pending interrupt enable */
  CAN_ITConfig(CAN, CAN_IT_FMP0, ENABLE);

/* transmit */
  TxMessage.StdId = 1;
  TxMessage.ExtId = 0;
  TxMessage.IDE = CAN_Id_Standard;
  TxMessage.RTR = CAN_RTR_DATA;
  TxMessage.DLC = 2;
  TxMessage.Data[0] = 0xCA;
  TxMessage.Data[1] = 0xFE;

  CAN_Transmit(CAN, &TxMessage);

flytent

问题解决了，官方例程里的注释为CAN总线频率为36MH在，这个注释是错误的，CAN是挂在APB总线上的，所以CAN总线的频率应该为48MHz，所以根据48MHz来计算波特率才对。
下面是250kbps的配置
/* CAN Baudrate = 1MBps (CAN clocked at 48 MHz) */
  CAN_InitStructure.CAN_BS1 = CAN_BS1_9tq;//CAN_BS1_9tq
  CAN_InitStructure.CAN_BS2 = CAN_BS2_2tq;//CAN_BS2_8tq
  CAN_InitStructure.CAN_Prescaler = 16;//2
  //  CAN_Baud_Process(500,&CAN_InitStructure);
  CAN_Init(CAN, &CAN_InitStructure);

lvkanger

用示波器量一下波形吧，看看Tx和Rx的波形

chunglin

CAN_H、CAN_L的连接有没有错
PC端和MCU端的波特率设置是否一致
终端电阻

flytent

lvkanger 发表于 2019-8-8 14:18
用示波器量一下波形吧，看看Tx和Rx的波形

示波器测了，072的高电平一直是高

flytent

chunglin 发表于 2019-8-8 16:06
CAN_H、CAN_L的连接有没有错
PC端和MCU端的波特率设置是否一致
终端电阻

刚用示波器测了072的TX引脚，输出一直是高

flytent

问题已解决。官方提供的例程里面的注释是错误的，官方注释CAN总线频率为36MHz，官方用户手册介绍CAN是挂在APB总线上，而APB总线是48MHz，所以波特率要根据48MHz来计算，不能根据36MHz计算。
如下配置，波特率为250kbps。
  /* CAN Baudrate = 1MBps (CAN clocked at 48 MHz) */
  CAN_InitStructure.CAN_BS1 = CAN_BS1_9tq;//CAN_BS1_9tq
  CAN_InitStructure.CAN_BS2 = CAN_BS2_2tq;//CAN_BS2_8tq
  CAN_InitStructure.CAN_Prescaler = 16;//2
  //  CAN_Baud_Process(500,&CAN_InitStructure);
  CAN_Init(CAN, &CAN_InitStructure);

技艺电子

发送数据是可以，就是接收数据有异常，中断不响应，读不到数据