CAN总线 Serial

不同的设备使用rt_device_write函数，会有问题出现

发布于 2022-05-05 16:19:22 浏览：1122 订阅该版

出出啊 2022-05-05

恃人不如自恃，人之为己者不如己之自为也

吕蛋蛋 2022-05-05

这家伙很懒，什么也没写！

吕蛋蛋 2022-05-05

这家伙很懒，什么也没写！

吕蛋蛋 2022-05-05

这家伙很懒，什么也没写！

lchnu 2022-05-05

Witness, Understand, Skill

出出啊 2022-05-06

恃人不如自恃，人之为己者不如己之自为也

吕蛋蛋 2022-05-06

这家伙很懒，什么也没写！

吕蛋蛋 2022-05-06

这家伙很懒，什么也没写！

@出出啊 还有一个情况是size返回值判断那地方，如果我把if里面的输出语句注释掉，程序会卡死在rt_device_write这里面，如果我取消注释，程序就能够正常运行```
static void can_tx_thread(void *parameter)
{
    struct rt_can_msg msg = {0};
    rt_size_t  size;

while(1)
    {
        rt_sem_take(&timer0_sem,RT_WAITING_FOREVER);

if(rt_mutex_take(&rx_can1_mutex, RT_WAITING_NO) == RT_EOK)
        {
            if((tmp_msg_can1.lcd_write_blade[3] == 0x02) && ((tmp_msg_can1.lcd_write_blade[4] - 1) == Switch_load(1, led_Switch)))
            {
                LOG_E("lcd_write_blade success...\n");
                msg.id = (tmp_msg_can1.lcd_write_blade[5] + 0x100);           //    ID 为 0x78
                msg.ide = RT_CAN_STDID;     // 标准格式
                msg.rtr = RT_CAN_DTR;       // 数据帧
                msg.len = 2;                // 数据长度为 8
                msg.data[0] = tmp_msg_can1.lcd_write_blade[6];                     //待发送的 8 字节数据
                msg.data[1] = tmp_msg_can1.lcd_write_blade[7];
                msg.data[2] = 0;
                msg.data[3] = 0;
                msg.data[4] = 0;
                msg.data[5] = 0;
                msg.data[6] = 0;
                msg.data[7] = 0;
                // 发送一帧 CAN 数据

rt_mutex_release(&rx_can1_mutex);

size = rt_device_write(can_dev, 0, &msg, sizeof(msg));

if (size == 0)
                {
                    rt_kprintf("lcd write can failed!\n");
                }
                rt_memset(tmp_msg_can1.lcd_write_blade, 0, 10);
            }
            else if ((tmp_msg_can1.lcd_write_blade[3] == 0x03) && ((tmp_msg_can1.lcd_write_blade[4] - 1) == Switch_load(1, led_Switch)))
            {
                LOG_E("many lcd write balde sucess...\n");
                msg.id = 0x91;           //    ID 为 0x78
                msg.ide = RT_CAN_STDID;     // 标准格式
                msg.rtr = RT_CAN_DTR;       // 数据帧
                msg.len = 2;                // 数据长度为 8
                msg.data[0] = tmp_msg_can1.lcd_write_blade[5];                     //待发送的 8 字节数据
                msg.data[1] = tmp_msg_can1.lcd_write_blade[6];
                msg.data[2] = 0;
                msg.data[3] = 0;
                msg.data[4] = 0;
                msg.data[5] = 0;
                msg.data[6] = 0;
                msg.data[7] = 0;
                // 发送一帧 CAN 数据
                rt_mutex_release(&rx_can1_mutex);

size = rt_device_write(can_dev, 0, &msg, sizeof(msg));

if (size == 0)
                {
                    rt_kprintf("lcd write can lot size failed!\n");
                }
                rt_memset(tmp_msg_can1.lcd_write_blade, 0, 10);
            }
        }
        if(rt_mutex_take(&rx_cdm_mutex, RT_WAITING_FOREVER) == RT_EOK)
        {
            msg.id = 0x90;           //    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
            msg.data[0] = (modbus_cdm.cdm_reginput_rev[0] >> 8 & 0xff);                     //待发送的 8 字节数据
            msg.data[1] = modbus_cdm.cdm_reginput_rev[0] & 0xff;
            msg.data[2] = (modbus_cdm.cdm_reginput_rev[1] >> 8 & 0xff);
            msg.data[3] = modbus_cdm.cdm_reginput_rev[1] & 0xff;
            msg.data[4] = 0;
            msg.data[5] = 0;
            msg.data[6] = 0;
            msg.data[7] = 0;
            // 发送一帧 CAN 数据
            rt_mutex_release(&rx_cdm_mutex);

size = rt_device_write(can_dev, 0, &msg, sizeof(msg));

if (size == 0)
            {
                rt_kprintf("%d\n",Switch_load(1, led_Switch));
                rt_kprintf("cdm write can1 data failed!\n");
            }
            else {
                rt_kprintf("%d\n",Switch_load(1, led_Switch));
                rt_kprintf("cdm write can1 data success...!\n");
            }
        }
    }
}
```