RT-Thread 如何使用can通信收发多字节数据（&gt;8字节）

发布于 2024-01-08 14:12:13 浏览：759 订阅该版

2 个回答

踩姑娘的小蘑菇 2024-01-08

这家伙很懒，什么也没写！

青灯 2024-01-08

这家伙很懒，什么也没写！

```c
#include <rtthread.h>
#include <rtdevice.h>
#define CAN_DEVICE_NAME "can1"
#define DATA_LENGTH     8   // 每个帧中的数据长度
#define size_t     rt_size_t
#define uint8_t     rt_uint8_t

typedef struct
{
    rt_uint32_t id;   // 帧 ID
    uint8_t data[DATA_LENGTH];   // 帧数据
} can_frame_t;

void can_send_frames(const can_frame_t* frames, size_t count)
{
    rt_device_t can_device;
    size_t send_count = 0;
    rt_size_t size;
    // 查找指定名称的 CAN 设备
    can_device = rt_device_find(CAN_DEVICE_NAME);
    if (can_device == RT_NULL)
    {
        rt_kprintf("Cannot find CAN device: %s\n", CAN_DEVICE_NAME);
        return;
    }

// 打开 CAN 设备
    if (rt_device_open(can_device, RT_DEVICE_FLAG_WRONLY) != RT_EOK)
    {
        rt_kprintf("Failed to open CAN device: %s\n", CAN_DEVICE_NAME);
        return;
    }

// 发送多帧数据
    while (send_count < count)
    {
        const can_frame_t* frame = &frames[send_count];

struct rt_can_msg msg;
        msg.ide = RT_CAN_STDID;   // 使用标准帧 ID
        msg.rtr = 0;              // 非远程帧
        msg.len = DATA_LENGTH;    // 数据长度
        msg.id = frame->id;       // 帧 ID
        memcpy(msg.data, frame->data, DATA_LENGTH);   // 帧数据
            // 发送数据
            size = rt_device_write(can_device, 0, frame->data, msg.len);
            if (size == msg.len)
            {
                rt_kprintf("\nSent %d bytes CAN.\n", size);
            }
        send_count++;
    }

// 关闭 CAN 设备
    rt_device_close(can_device);
}

int main(void)
{
    can_frame_t send_frames[] =
    {
        { 0x100, { 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08 } },
        { 0x101, { 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18 } },
        // ...
    };
    size_t send_frame_count = sizeof(send_frames) / sizeof(send_frames[0]);

// 发送多帧数据
    can_send_frames(send_frames, send_frame_count);
}
```
调试发现            `size = rt_device_write(can_device, 0, frame->data, msg.len);`这里size一直是0，两帧数据是对的，`- 1`.