stm32 - STM32 虚拟串口有什么问题？我打不开

Question

我有 Nucleo STM32H743ZI 开发板。我正在使用 CubeMX HAL(我尝试了几个版本)和 TrueStudio。 Windows 10 中出现“虚拟 COM 端口”(我尝试了默认的 Windows 驱动程序和 ST 驱动程序)但我无法打开端口。我的 C# 程序在我尝试打开它时写给我“参数不正确”:

SerialPort port = new SerialPort("COM8", 9600, Parity.None, 8, StopBits.One);
port.Open(); // System.IO.IOException: 'The parameter is incorrect.'

同样的消息写给我程序 Realterm，PuTTY 什么都不做，“Tera Term”程序正常工作——我可以向我的 MCU 程序发送和接收数据。

谁知道是什么？

在我的 C# 程序和终端程序中我使用相同的参数

USB 设备查看器信息:

            [Port1]  :  STMicroelectronics Virtual COM Port


            Is Port User Connectable:         yes
            Is Port Debug Capable:            no
            Companion Port Number:            17
            Companion Hub Symbolic Link Name: USB#ROOT_HUB30#4&2f29167c&0&0#{f18a0e88-c30c-11d0-8815-00a0c906bed8}
            Protocols Supported:
             USB 1.1:                         yes
             USB 2.0:                         yes
             USB 3.0:                         no

            Device Power State:               PowerDeviceD0

                   ---===>Device Information<===---
            English product name: "STM32 Virtual ComPort"

            ConnectionStatus:                  
            Current Config Value:              0x01  -> Device Bus Speed: Full (is not SuperSpeed or higher capable)
            Device Address:                    0x0A
            Open Pipes:                           3

                      ===>Device Descriptor<===
            bLength:                           0x12
            bDescriptorType:                   0x01
            bcdUSB:                          0x0200
            bDeviceClass:                      0x02  -> This is a Communication Device
            bDeviceSubClass:                   0x00
            bDeviceProtocol:                   0x00
            bMaxPacketSize0:                   0x40 = (64) Bytes
            idVendor:                        0x0483 = STMicroelectronics
            idProduct:                       0x5740
            bcdDevice:                       0x0200
            iManufacturer:                     0x01
                 English (United States)  "STMicroelectronics"
            iProduct:                          0x02
                 English (United States)  "STM32 Virtual ComPort"
            iSerialNumber:                     0x03
                 English (United States)  "354BB9433137"
            bNumConfigurations:                0x01

                      ---===>Open Pipes<===---

                      ===>Endpoint Descriptor<===
            bLength:                           0x07
            bDescriptorType:                   0x05
            bEndpointAddress:                  0x82  -> Direction: IN - EndpointID: 2
            bmAttributes:                      0x03  -> Interrupt Transfer Type
            wMaxPacketSize:                  0x0008 = 0x08 bytes
            bInterval:                         0x10

                      ===>Endpoint Descriptor<===
            bLength:                           0x07
            bDescriptorType:                   0x05
            bEndpointAddress:                  0x01  -> Direction: OUT - EndpointID: 1
            bmAttributes:                      0x02  -> Bulk Transfer Type
            wMaxPacketSize:                  0x0040 = 0x40 bytes
            bInterval:                         0x00

                      ===>Endpoint Descriptor<===
            bLength:                           0x07
            bDescriptorType:                   0x05
            bEndpointAddress:                  0x81  -> Direction: IN - EndpointID: 1
            bmAttributes:                      0x02  -> Bulk Transfer Type
            wMaxPacketSize:                  0x0040 = 0x40 bytes
            bInterval:                         0x00

                   ---===>Full Configuration Descriptor<===---

                      ===>Configuration Descriptor<===
            bLength:                           0x09
            bDescriptorType:                   0x02
            wTotalLength:                    0x0043  -> Validated
            bNumInterfaces:                    0x02
            bConfigurationValue:               0x01
            iConfiguration:                    0x00
            bmAttributes:                      0xC0  -> Self Powered
            MaxPower:                          0x32 = 100 mA

                      ===>Interface Descriptor<===
            bLength:                           0x09
            bDescriptorType:                   0x04
            bInterfaceNumber:                  0x00
            bAlternateSetting:                 0x00
            bNumEndpoints:                     0x01
            bInterfaceClass:                   0x02  -> This is Communications (CDC Control) USB Device Interface Class
            bInterfaceSubClass:                0x02
            bInterfaceProtocol:                0x01
            iInterface:                        0x00
              -> This is a Communications (CDC Control) USB Device Interface Class

                      ===>Descriptor Hex Dump<===
            bLength:                           0x05
            bDescriptorType:                   0x24
            05 24 00 10 01 
              -> This is a Communications (CDC Control) USB Device Interface Class

                      ===>Descriptor Hex Dump<===
            bLength:                           0x05
            bDescriptorType:                   0x24
            05 24 01 00 01 
              -> This is a Communications (CDC Control) USB Device Interface Class

                      ===>Descriptor Hex Dump<===
            bLength:                           0x04
            bDescriptorType:                   0x24
            04 24 02 02 
              -> This is a Communications (CDC Control) USB Device Interface Class

                      ===>Descriptor Hex Dump<===
            bLength:                           0x05
            bDescriptorType:                   0x24
            05 24 06 00 01 

                      ===>Endpoint Descriptor<===
            bLength:                           0x07
            bDescriptorType:                   0x05
            bEndpointAddress:                  0x82  -> Direction: IN - EndpointID: 2
            bmAttributes:                      0x03  -> Interrupt Transfer Type
            wMaxPacketSize:                  0x0008 = 0x08 bytes
            bInterval:                         0x10

                      ===>Interface Descriptor<===
            bLength:                           0x09
            bDescriptorType:                   0x04
            bInterfaceNumber:                  0x01
            bAlternateSetting:                 0x00
            bNumEndpoints:                     0x02
            bInterfaceClass:                   0x0A  -> This is a CDC Data USB Device Interface Class
            bInterfaceSubClass:                0x00
            bInterfaceProtocol:                0x00
            iInterface:                        0x00

                      ===>Endpoint Descriptor<===
            bLength:                           0x07
            bDescriptorType:                   0x05
            bEndpointAddress:                  0x01  -> Direction: OUT - EndpointID: 1
            bmAttributes:                      0x02  -> Bulk Transfer Type
            wMaxPacketSize:                  0x0040 = 0x40 bytes
            bInterval:                         0x00

                      ===>Endpoint Descriptor<===
            bLength:                           0x07
            bDescriptorType:                   0x05
            bEndpointAddress:                  0x81  -> Direction: IN - EndpointID: 1
            bmAttributes:                      0x02  -> Bulk Transfer Type
            wMaxPacketSize:                  0x0040 = 0x40 bytes
            bInterval:                         0x00

Answer 1

我有同样的问题，我可以读取设备并查看哪个 com 端口，但我无法打开一个。 (对于 CDC)

然后我遇到了以下帖子，最后一个答案解决了我的问题: https://community.st.com/s/question/0D50X00009XkgIYSAZ/unable-to-configure-serial-port-error-for-usb-cdc

那里提到如果你想通过 VCP 进行 RS232 通信，你需要添加几行。

我在 usbd_cdc_if.c 文件中添加了以下内容:

/*******************************************************************************/
/* Line Coding Structure                                                       */
/*-----------------------------------------------------------------------------*/
/* Offset | Field       | Size | Value  | Description                          */
/* 0      | dwDTERate   |   4  | Number |Data terminal rate, in bits per second*/
/* 4      | bCharFormat |   1  | Number | Stop bits                            */
/*                                        0 - 1 Stop bit                       */
/*                                        1 - 1.5 Stop bits                    */
/*                                        2 - 2 Stop bits                      */
/* 5      | bParityType |  1   | Number | Parity                               */
/*                                        0 - None                             */
/*                                        1 - Odd                              */
/*                                        2 - Even                             */
/*                                        3 - Mark                             */
/*                                        4 - Space                            */
/* 6      | bDataBits  |   1   | Number Data bits (5, 6, 7, 8 or 16).          */
/*******************************************************************************/
static uint8_t lineCoding[7] // 115200bps, 1stop, no parity, 8bit
    = { 0x00, 0xC2, 0x01, 0x00, 0x00, 0x00, 0x08 };

并调整了 CDC_Control_FS 函数:

static int8_t CDC_Control_FS(uint8_t cmd, uint8_t* pbuf, uint16_t length)
{
  /* USER CODE BEGIN 5 */
  switch(cmd)
  {
   ...
    case CDC_SET_LINE_CODING:
      memcpy(lineCoding, pbuf, sizeof(lineCoding));
    break;

    case CDC_GET_LINE_CODING:
      memcpy(pbuf, lineCoding, sizeof(lineCoding));
    break;
    ...
}

我希望这对你仍然有用。