RT-Thread-ART-PI FDCAN 使用RT-Thread问答社区

ART-PI FDCAN 使用

发布于 2023-02-17 14:32:03 浏览：910 订阅该版

[tocm]

# 1.FDCAN设备添加
	如下图所示，使用RT-Thread Setting 添加默认的FDCAN1设备，保存并重新构建到工程；
![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20230217/eb0f92d3c837245924090dad19dda19a.png.webp)
# 2.修改波特率配置
1. 检查系统时钟配置，确认can输入时钟为80Mhz，如下图所示：
![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20230217/e95919a8421b3e339acd9d6960a95ea6.png.webp)

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20230217/453ec108e6290864fff5effebf9ee477.png.webp)
2. 修改drv_fdcan.c文件，由于本文使用的是500K的波特率，故只改了一小部分。

```c

static const _stm32_fdcan_NTconfig_t st_CanNTconfig[]=
/*baud brp sjw tseg1 tseg2*/
{
	{CAN1MBaud,     1,8,63,16},
	{CAN800kBaud,   10,8,20,4},
	{CAN500kBaud,   2,8,63,16},
	{CAN250kBaud,   20,8,35,4},
	{CAN125kBaud,   40,8,35,4},
	{CAN100kBaud,   40,8,44,5},
	{CAN50kBaud,    80,8,44,5},
	{CAN20kBaud,    200,8,44,5},
	{CAN10kBaud,    400,8,44,5}
};
```
3. 修改drv_fdcan.c文件下的FDCAN_MODE_INTERNAL_LOOPBACK，改为FDCAN_MODE_EXTERNAL_LOOPBACK；此项改动为防止FDCAN在回环模式下TX没有输出信号；
	
```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_LISEN:
		pdrv_can->fdcanHandle.Init.Mode = FDCAN_MODE_BUS_MONITORING;
		break;
	case RT_CAN_MODE_LOOPBACK:
		pdrv_can->fdcanHandle.Init.Mode = FDCAN_MODE_EXTERNAL_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;

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;
}

```
# 3.添加外设软件包
1. 使用RT-Thread Setting 添加【rtthread设备驱动使用示例】软件包，在搜索框中搜索samples也可以找到，配置如下图所示；

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20230217/cc28d28ae6f75e1f26d26a82242c004f.png.webp)
2.添加完成后，查看can_sample.c文件，如下图所示；

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20230217/825e9a92504dceb6f983c5e263750f07.png.webp)
3.修改can_sample.c文件，代码如下，主要是将can1设备改为fdcan1,并增加设置can波特率语句。

```c
#include <rtdevice.h>
#include <rtthread.h>
#define CAN_DEV_NAME       "fdcan1"      /* CAN 设备名称 */

static struct rt_semaphore rx_sem;     /* 用于接收消息的信号量 */
static rt_device_t can_dev;            /* CAN 设备句柄 */

/* 接收数据回调函数 */
static rt_err_t can_rx_call(rt_device_t dev, rt_size_t size)
{
    /* CAN 接收到数据后产生中断，调用此回调函数，然后发送接收信号量 */
    rt_sem_release(&rx_sem);

return RT_EOK;
}

static void can_rx_thread(void *parameter)
{
    int i;
    rt_err_t res;
    struct rt_can_msg rxmsg = {0};

/* 设置接收回调函数 */
    rt_device_set_rx_indicate(can_dev, can_rx_call);

#ifdef RT_CAN_USING_HDR
    struct rt_can_filter_item items[5] =
    {
        RT_CAN_FILTER_ITEM_INIT(0x100, 0, 0, 0, 0x700, RT_NULL, RT_NULL), /* std,match ID:0x100~0x1ff，hdr 为 - 1，设置默认过滤表 */
        RT_CAN_FILTER_ITEM_INIT(0x300, 0, 0, 0, 0x700, RT_NULL, RT_NULL), /* std,match ID:0x300~0x3ff，hdr 为 - 1 */
        RT_CAN_FILTER_ITEM_INIT(0x211, 0, 0, 0, 0x7ff, RT_NULL, RT_NULL), /* std,match ID:0x211，hdr 为 - 1 */
        RT_CAN_FILTER_STD_INIT(0x486, RT_NULL, RT_NULL),                  /* std,match ID:0x486，hdr 为 - 1 */
        {0x555, 0, 0, 0, 0x7ff, 7,}                                       /* std,match ID:0x555，hdr 为 7，指定设置 7 号过滤表 */
    };
    struct rt_can_filter_config cfg = {5, 1, items}; /* 一共有 5 个过滤表 */
    /* 设置硬件过滤表 */
    res = rt_device_control(can_dev, RT_CAN_CMD_SET_FILTER, &cfg);
    RT_ASSERT(res == RT_EOK);
#endif

while (1)
    {
        /* hdr 值为 - 1，表示直接从 uselist 链表读取数据 */
        rxmsg.hdr = -1;
        /* 阻塞等待接收信号量 */
        rt_sem_take(&rx_sem, RT_WAITING_FOREVER);
        /* 从 CAN 读取一帧数据 */
        rt_device_read(can_dev, 0, &rxmsg, sizeof(rxmsg));
        /* 打印数据 ID 及内容 */
        rt_kprintf("ID:%x", rxmsg.id);
        for (i = 0; i < 8; i++)
        {
            rt_kprintf("%2x", rxmsg.data[i]);
        }

rt_kprintf("\n");
    }
}

int mycan_sample(int argc, char *argv[])
{
    struct rt_can_msg msg = {0};
    rt_err_t res;
    rt_size_t  size;
    rt_thread_t thread;
    char can_name[RT_NAME_MAX];

if (argc == 2)
    {
        rt_strncpy(can_name, argv[1], RT_NAME_MAX);
    }
    else
    {
        rt_strncpy(can_name, CAN_DEV_NAME, RT_NAME_MAX);
    }
    /* 查找 CAN 设备 */
    can_dev = rt_device_find(can_name);
    if (!can_dev)
    {
        rt_kprintf("find %s failed!\n", can_name);
        return RT_ERROR;
    }

/* 初始化 CAN 接收信号量 */
    rt_sem_init(&rx_sem, "rx_sem", 0, RT_IPC_FLAG_FIFO);

/* 以中断接收及发送方式打开 CAN 设备 */
    res = rt_device_open(can_dev, RT_DEVICE_FLAG_INT_TX | RT_DEVICE_FLAG_INT_RX);
    RT_ASSERT(res == RT_EOK);

/* 设置 CAN 通信的波特率为 500kbit/s*/
    res = rt_device_control(can_dev, RT_CAN_CMD_SET_BAUD, (void *)CAN500kBaud);
    RT_ASSERT(res == RT_EOK);
    /* 创建数据接收线程 */
    thread = rt_thread_create("can_rx", can_rx_thread, RT_NULL, 1024, 25, 10);
    if (thread != RT_NULL)
    {
        rt_thread_startup(thread);
    }
    else
    {
        rt_kprintf("create can_rx thread failed!\n");
    }

msg.id = 0x78;              /* ID 为 0x78 */
    msg.ide = RT_CAN_STDID;     /* 标准格式 */
    msg.rtr = RT_CAN_DTR;       /* 数据帧 */
    msg.len = 8;                /* 数据长度为 8 */
    /* 待发送的 8 字节数据 */
    msg.data[0] = 0x00;
    msg.data[1] = 0x11;
    msg.data[2] = 0x22;
    msg.data[3] = 0x33;
    msg.data[4] = 0x44;
    msg.data[5] = 0x55;
    msg.data[6] = 0x66;
    msg.data[7] = 0x77;
    /* 发送一帧 CAN 数据 */
    size = rt_device_write(can_dev, 0, &msg, sizeof(msg));
    if (size == 0)
    {
        rt_kprintf("can dev write data failed!\n");
    }

return res;
}
/* 导出到 msh 命令列表中 */
MSH_CMD_EXPORT(mycan_sample, can device sample);

```
4.测试结果

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20230217/20cb2b10a0aced6df28d40f5b269c67a.png.webp)
注意：再次使用命令启动该示例会有以下提示：

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20230217/49b66a3a6aa352d761b880db4a4a0ecd.png)