RT-Thread-stm32H750 FDCAN无法发送数据，但是帧ID可以发送RT-Thread问答社区

5 stm32H750 FDCAN无法发送数据，但是帧ID可以发送

发布于 2024-11-11 17:45:45 浏览：34 订阅该版

使用官方提供的drv_fdcan例程配置好，能发送帧id，但是DLC和数据一直为0.如下图：

![企业微信截图_17313180023929.png](https://oss-club.rt-thread.org/uploads/20241111/d694ae166dfb3b8ac69a4aa933efec6f.png.webp)

发送数据前打印出来，确保数据前端没问题，如下图：

![企业微信截图_17313180023929.png](https://oss-club.rt-thread.org/uploads/20241111/01b6df074ebd24b5176bc2fd1b405785.png)
初始化代码使用官方的不行，使用正点原子的也不行（正点原子独立的工程可以正常收发fdcan数据）
初始化代码如下：

```c
static rt_err_t _inline_can_config(struct rt_can_device *can, struct can_configure *cfg)
{
	_stm32_fdcan_t *pdrv_can;
	rt_uint32_t tmp_u32Index;

RT_ASSERT(can);
	RT_ASSERT(cfg);

pdrv_can = (_stm32_fdcan_t *)can->parent.user_data;

RT_ASSERT(pdrv_can);

pdrv_can->fdcanHandle.Init.FrameFormat = FDCAN_FRAME_CLASSIC;
	pdrv_can->fdcanHandle.Init.Mode = FDCAN_MODE_NORMAL;
	pdrv_can->fdcanHandle.Init.AutoRetransmission = DISABLE;
	pdrv_can->fdcanHandle.Init.TransmitPause = DISABLE;
	pdrv_can->fdcanHandle.Init.ProtocolException = DISABLE;

switch (cfg->mode)
	{
	case RT_CAN_MODE_NORMAL:
		pdrv_can->fdcanHandle.Init.Mode = FDCAN_MODE_NORMAL;
		break;
	case RT_CAN_MODE_LISTEN:
		pdrv_can->fdcanHandle.Init.Mode = FDCAN_MODE_BUS_MONITORING;
		break;
	case RT_CAN_MODE_LOOPBACK:
		pdrv_can->fdcanHandle.Init.Mode = FDCAN_MODE_INTERNAL_LOOPBACK;
		break;
	default:
		pdrv_can->fdcanHandle.Init.Mode = FDCAN_MODE_NORMAL;
		break;
	}

/*config baud rate*/
	tmp_u32Index = _inline_get_NTbaud_index(cfg->baud_rate);

pdrv_can->fdcanHandle.Init.NominalPrescaler = st_CanNTconfig[tmp_u32Index].u16Nbrp;
	pdrv_can->fdcanHandle.Init.NominalSyncJumpWidth = st_CanNTconfig[tmp_u32Index].u8Nsjw;
	pdrv_can->fdcanHandle.Init.NominalTimeSeg1 = st_CanNTconfig[tmp_u32Index].u8Ntseg1;
	pdrv_can->fdcanHandle.Init.NominalTimeSeg2 = st_CanNTconfig[tmp_u32Index].u8Ntseg2;
	
//	if(pdrv_can->fdcanHandle.Instance == FDCAN1)
//	{
//		pdrv_can->fdcanHandle.Init.MessageRAMOffset = 0;					
//	}
//	else
//	{
//		pdrv_can->fdcanHandle.Init.MessageRAMOffset = 1280;					
//	}
//	pdrv_can->fdcanHandle.Init.StdFiltersNbr = 2;							
//	pdrv_can->fdcanHandle.Init.ExtFiltersNbr = 2;							
//	pdrv_can->fdcanHandle.Init.RxFifo0ElmtsNbr = 1;							
//	pdrv_can->fdcanHandle.Init.RxFifo0ElmtSize = FDCAN_DATA_BYTES_8;		
//	pdrv_can->fdcanHandle.Init.RxBuffersNbr = 0;							
//	pdrv_can->fdcanHandle.Init.TxEventsNbr = 0;								
//	pdrv_can->fdcanHandle.Init.TxBuffersNbr = 3;							
//	pdrv_can->fdcanHandle.Init.TxFifoQueueElmtsNbr = 0;						
//	pdrv_can->fdcanHandle.Init.TxFifoQueueMode = FDCAN_TX_FIFO_OPERATION;	
//	pdrv_can->fdcanHandle.Init.TxElmtSize = FDCAN_DATA_BYTES_8;

pdrv_can->fdcanHandle.Init.DataPrescaler = 1;                            /* 数据比特率预分频系数 */
	  pdrv_can->fdcanHandle.Init.DataSyncJumpWidth = 1;                        /* 同步跳转宽度 */
	  pdrv_can->fdcanHandle.Init.DataTimeSeg1 = 1;                             /* 采样点之前的数据时间段 */
	  pdrv_can->fdcanHandle.Init.DataTimeSeg2 = 1;                             /* 采样点之后的数据时间段 */
    pdrv_can->fdcanHandle.Init.MessageRAMOffset = 0;                         /* 消息RAM地址偏移 */
    pdrv_can->fdcanHandle.Init.StdFiltersNbr = 0;                            /* 标准消息ID滤波器数量 */
    pdrv_can->fdcanHandle.Init.ExtFiltersNbr = 0;                            /* 扩展消息ID滤波器数量 */
    pdrv_can->fdcanHandle.Init.RxFifo0ElmtsNbr = 1;                          /* 接收FiFo0元素数量 */
    pdrv_can->fdcanHandle.Init.RxFifo0ElmtSize = FDCAN_DATA_BYTES_8;         /* 接收FiFo0元素大小 */
    pdrv_can->fdcanHandle.Init.RxFifo1ElmtsNbr = 0;                          /* 接收FiFo1元素数量 */
    pdrv_can->fdcanHandle.Init.RxFifo1ElmtSize = FDCAN_DATA_BYTES_8;         /* 接收FiFo1元素大小 */
    pdrv_can->fdcanHandle.Init.RxBuffersNbr = 0;                             /* 专用接收缓冲区元素数量 */
    pdrv_can->fdcanHandle.Init.RxBufferSize = FDCAN_DATA_BYTES_8;            /* 专用接收缓冲区元素大小 */
    pdrv_can->fdcanHandle.Init.TxEventsNbr = 0;                              /* 发送事件FiFo元素数量 */
    pdrv_can->fdcanHandle.Init.TxBuffersNbr = 0;                             /* 专用发送缓冲区数量 */
    pdrv_can->fdcanHandle.Init.TxFifoQueueElmtsNbr = 1;                      /* 发送序列/FiFo缓冲区数量 */
    pdrv_can->fdcanHandle.Init.TxFifoQueueMode = FDCAN_TX_FIFO_OPERATION;    /* 发送序列/FiFo模式 */
    pdrv_can->fdcanHandle.Init.TxElmtSize = FDCAN_DATA_BYTES_8;              /* 发送元素大小 */	
	
	if (HAL_FDCAN_Init(&pdrv_can->fdcanHandle) != HAL_OK)
	{
		return -RT_ERROR;
	}
	/* default filter config */
	HAL_FDCAN_ConfigFilter(&pdrv_can->fdcanHandle , &pdrv_can->FilterConfig);
	/*init fdcan tx header*/
	_inline_can_tx_header_init(pdrv_can);
	/* can start */
	HAL_FDCAN_Start(&pdrv_can->fdcanHandle);
	return RT_EOK;
}
```

发送部分代码如下，也是使用官方的不行（正点原子的也不行）：

```c
static rt_ssize_t _inline_can_sendmsg(struct rt_can_device *can, const void *buf, rt_uint32_t box_num)
{

_stm32_fdcan_t *pdrv_can;
	struct rt_can_msg *pmsg;
	uint32_t tmp_u32DataLen;
	RT_ASSERT(can);
	RT_ASSERT(buf);

pdrv_can = (_stm32_fdcan_t *)can->parent.user_data;

RT_ASSERT(pdrv_can);

pmsg = (struct rt_can_msg *) buf;

/* Check the parameters */
	if(pmsg->len > 8)
	{
		tmp_u32DataLen = 8;
	}
	else
	{
		tmp_u32DataLen = pmsg->len;
	}
	tmp_u32DataLen <<=16;
	rt_kprintf("fdcan sends message id.0x%08x;\n",pmsg->id);
	rt_kprintf("fdcan sends message len.%2.2x; message date:\n",pmsg->len);
  for(int i = 0; i < pmsg->len; i++){
		rt_kprintf(" %2.2x ",pmsg->data[i]);
	}
	rt_kprintf("\n");
	
	if(pmsg->ide == RT_CAN_EXTID)
	{
		pdrv_can->TxHeader.IdType = FDCAN_EXTENDED_ID;
	}
	else
	{
		pdrv_can->TxHeader.IdType = FDCAN_STANDARD_ID;
	}
	if (RT_CAN_DTR == pmsg->rtr)
	{
		pdrv_can->TxHeader.TxFrameType = FDCAN_DATA_FRAME;
	}
	else
	{
		pdrv_can->TxHeader.TxFrameType = FDCAN_REMOTE_FRAME;
	}

pdrv_can->TxHeader.Identifier = pmsg->id;
	pdrv_can->TxHeader.DataLength = tmp_u32DataLen;
	  
	pdrv_can->TxHeader.Identifier = pmsg->id;                   /* ID */
	pdrv_can->TxHeader.IdType = FDCAN_STANDARD_ID;              /* ID类型 */
	pdrv_can->TxHeader.TxFrameType = FDCAN_DATA_FRAME;          /* 帧类型 */
	pdrv_can->TxHeader.DataLength = tmp_u32DataLen;             /* 帧长度 */
	pdrv_can->TxHeader.ErrorStateIndicator = FDCAN_ESI_ACTIVE;  /* 错误状态指示器 */
	pdrv_can->TxHeader.BitRateSwitch = FDCAN_BRS_OFF;           /* 比特率切换 */
	pdrv_can->TxHeader.FDFormat = FDCAN_CLASSIC_CAN;            /* 格式 */
	pdrv_can->TxHeader.TxEventFifoControl = FDCAN_NO_TX_EVENTS; /* 事件FiFo控制 */
	pdrv_can->TxHeader.MessageMarker = 0;                       /* 消息掩码 */
	
	if (HAL_FDCAN_AddMessageToTxFifoQ(&pdrv_can->fdcanHandle, &pdrv_can->TxHeader, pmsg->data) != HAL_OK)
	{
			return -RT_ERROR;
	}
	return RT_EOK;
//	if(HAL_FDCAN_AddMessageToTxBuffer(&pdrv_can->fdcanHandle, &pdrv_can->TxHeader, pmsg->data, FDCAN_TX_BUFFER0+box_num) != HAL_OK)
//	{
//		return -RT_ERROR;
//	}
//	else
//	{
//		/* Request transmission */
//		HAL_FDCAN_EnableTxBufferRequest(&pdrv_can->fdcanHandle,FDCAN_TX_BUFFER0+box_num);
//		return RT_EOK;
//	}
}
```