沁恒CH32x RT-Thread驱动添加适配CH32V208驱动-电子发烧友网 (elecfans.com)
在这个基础上，我增加了适配CAN的驱动，接着就可以篇写CAN驱动，来实现数据收发了。

配置

1. 打开env工具，输入menuconfig,打开图形配置界面，选择Hardware Drivers Conifg---->On-chip Peripheral Drivers-->Enable CAN-->启动Using CAN1
   
2. 添加 can测试文件。用vscode打开rtthread目录添加can_sample.c函数如下：

/*
 * Copyright (c) 2006-2021, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author       Notes
 * 2023-02-01     Administrator       the first version
 */
/*
 * 程序清单：这是一个 CAN 设备使用例程
 * 例程导出了 can_sample 命令到控制终端
 * 命令调用格式：can_sample can1
 * 命令解释：命令第二个参数是要使用的 CAN 设备名称，为空则使用默认的 CAN 设备
 * 程序功能：通过 CAN 设备发送一帧，并创建一个线程接收数据然后打印输出。
*/

#include <rtthread.h>
#include "rtdevice.h"

#define CAN_DEV_NAME       "can1"      /* 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;
}

int can_send(rt_uint32_t humi,rt_uint32_t temp)
{
    struct rt_can_msg msg = {0};
    rt_err_t res;
    rt_size_t  size;
    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] = (uint8_t)(temp/100);
       msg.data[1] = (uint8_t)(temp%100);
       msg.data[2] = (uint8_t)(humi/100);
       msg.data[3] = (uint8_t)(humi%100);
       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;
}

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_index = -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("recv end\n");
    }
}

int can_sample(void)
{
    struct rt_can_msg msg = {0};
    rt_err_t res;
    rt_size_t  size;
    rt_thread_t thread;
    char can_name[RT_NAME_MAX];

    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);
    /* 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);
    /* 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);
    /* 创建数据接收线程 */
    thread = rt_thread_create("can_rx", can_rx_thread, RT_NULL, 2056, 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");
    }

    rt_kprintf("can dev write data OK !\n");
    return res;
}
/* 导出到 msh 命令列表中 */
MSH_CMD_EXPORT(can_sample, can device sample);

3. 在env工具中输入scons执行编译：

4. 然后打开wchisp工具把rtthread.bin下载到开发板：
   
5. 用CAN转TTL连接到CAN分析仪上，打开调试软件，以及msh终端：
   

【总结】
虽然wch在rtthread的驱动没有更新，但是经过我的修复，顺利的完成CAN的测试工作。