[问答]

虚拟串口与STM32通信遇到的疑问求解

问答对人有帮助，内容完整，我也想知道答案 0 我想要一个虚拟串口与STM32 通信。在其中，我需要从串口获取输入命令，然后实现命令想要做的事情。我在网上看到很多关于它的例子。然而，它们都在“CDC_Receive_FS”中获得消息并立即重新发送到PC。这意味着消息没有出去。例如，离开“usbd_cdc_if.c”并在“main.c”中发送给PC。如何在“CDC_Receive_FS”外部收到消息？如何避免丢失消息？ usbd_cdc_if.c /** * @brief Data received over USB OUT endpoint are sent over CDC interface * through this function. * * @note * This function will block any OUT packet reception on USB endpoint * untill exiting this function. If you exit this function before transfer * is complete on CDC interface (ie. using DMA controller) it will result * in receiving more data while previous ones are still not sent. * * @param Buf: Buffer of data to be received * @param Len: Number of data received (in bytes) * @retval Result of the operation: USBD_OK if all operations are OK else USBD_FAIL / static int8_t CDC_Receive_FS(uint8_t Buf, uint32_t Len) { / USER CODE BEGIN 6 / USBD_CDC_SetRxBuffer( hUsbDeviceFS, Buf[0]); USBD_CDC_ReceivePacket( hUsbDeviceFS); USBD_CDC_SetTxBuffer( hUsbDeviceFS, Buf, Len); USBD_CDC_TransmitPacket( hUsbDeviceFS); return (USBD_OK); / USER CODE END 6 / } 如何在main.c中使用“UserRxBufferFS”和“UserTxBufferFS”？ /* @defgroup USBD_CDC_IF_Private_Variables USBD_CDC_IF_Private_Variables * @brief Private variables. * @{ / / Create buffer for reception and transmission / / It's up to user to redefine and/or remove those define / /* Received data over USB are stored in this buffer / uint8_t UserRxBufferFS[APP_RX_DATA_SIZE]; /* Data to send over USB CDC are stored in this buffer / uint8_t UserTxBufferFS[APP_TX_DATA_SIZE]; [/td] 以下内容为评论 [td]我正在使用Blue Pill板。我在下面找到了例子。它教我成功在外面使用“UserRxBufferFS”和“ Len”。 / **************************************************************************** * @file : main.c * @brief : Main program body ****************************************************************************** * This notice applies to any and all portions of this file * that are not between comment pairs USER CODE BEGIN and * USER CODE END. Other portions of this file, whether * inserted by the user or by software development tools * are owned by their respective copyright owners. * * Copyright (c) 2018 STMicroelectronics International N.V. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted, provided that the following conditions are met: * * 1. Redistribution of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * 3. Neither the name of STMicroelectronics nor the names of other * contributors to this software may be used to endorse or promote products * derived from this software without specific written permission. * 4. This software, including modifications and/or derivative works of this * software, must execute solely and exclusively on microcontroller or * microprocessor devices manufactured by or for STMicroelectronics. * 5. Redistribution and use of this software other than as permitted under * this license is void and will automatically terminate your rights under * this license. * * THIS SOFTWARE IS PROVIDED BY STMICROELECTRONICS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS, IMPLIED OR STATUTORY WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A * PARTICULAR PURPOSE AND NON-INFRINGEMENT OF THIRD PARTY INTELLECTUAL PROPERTY * RIGHTS ARE DISCLAIMED TO THE FULLEST EXTENT PERMITTED BY LAW. IN NO EVENT * SHALL STMICROELECTRONICS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * ****************************************************************************** / / Includes ------------------------------------------------------------------/ #include "main.h" #include "stm32f1xx_hal.h" #include "usart.h" #include "usb_device.h" #include "gpio.h" / USER CODE BEGIN Includes / #include "usb_device.h" #include "usbd_core.h" #include "usbd_desc.h" #include "usbd_cdc.h" #include "usbd_cdc_if.h" / USER CODE END Includes / / Private variables ---------------------------------------------------------/ / USER CODE BEGIN PV / / Private variables ---------------------------------------------------------/ // http://www.smilefrog.net/?p=763 "USB-CDC (VCP)“ extern uint8_t UserRxBufferFS[]; // declare receive data external variable extern uint8_t DataLen; // declare receive buffer external variable / USER CODE END PV / / Private function prototypes -----------------------------------------------/ void SystemClock_Config(void); / USER CODE BEGIN PFP / / Private function prototypes -----------------------------------------------/ / USER CODE END PFP / / USER CODE BEGIN 0 / / USER CODE END 0 / /* * @brief The application entry point. * * @retval None / int main(void) { / USER CODE BEGIN 1 / / USER CODE END 1 / / MCU Configuration----------------------------------------------------------/ / Reset of all peripherals, Initializes the Flash interface and the Systick. / HAL_Init(); / USER CODE BEGIN Init / / USER CODE END Init / / Configure the system clock / SystemClock_Config(); / USER CODE BEGIN SysInit / / USER CODE END SysInit / / Initialize all configured peripherals / MX_GPIO_Init(); MX_USART1_UART_Init(); MX_USB_DEVICE_Init(); / USER CODE BEGIN 2 / / USER CODE END 2 / / Infinite loop / / USER CODE BEGIN WHILE / while (1) { / USER CODE END WHILE / / USER CODE BEGIN 3 / / to ensure the code is running / //HAL_GPIO_TogglePin(GPIOB, GPIO_PIN_12); //HAL_Delay(1000); if(DataLen > 0) { while(CDC_Transmit_FS(UserRxBufferFS, DataLen)); DataLen = 0; } } / USER CODE END 3 / } /* * @brief System Clock Configuration * @retval None / void SystemClock_Config(void) { RCC_OscInitTypeDef RCC_OscInitStruct; RCC_ClkInitTypeDef RCC_ClkInitStruct; RCC_PeriphCLKInitTypeDef PeriphClkInit; /Initializes the CPU, AHB and APB busses clocks / RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE; RCC_OscInitStruct.HSEState = RCC_HSE_ON; RCC_OscInitStruct.HSEPredivValue = RCC_HSE_PREDIV_DIV1; RCC_OscInitStruct.HSIState = RCC_HSI_ON; RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON; RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE; RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL9; if (HAL_RCC_OscConfig( RCC_OscInitStruct) != HAL_OK) { _Error_Handler(__FILE__, __LINE__); } /*Initializes the CPU, AHB and APB busses clocks / RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK\|RCC_CLOCKTYPE_SYSCLK \|RCC_CLOCKTYPE_PCLK1\|RCC_CLOCKTYPE_PCLK2; RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK; RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1; RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2; RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1; if (HAL_RCC_ClockConfig( RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK) { _Error_Handler(__FILE__, __LINE__); } PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_USB; PeriphClkInit.UsbClockSelection = RCC_USBCLKSOURCE_PLL_DIV1_5; if (HAL_RCCEx_PeriphCLKConfig( PeriphClkInit) != HAL_OK) { _Error_Handler(__FILE__, __LINE__); } /*Configure the Systick interrupt time / HAL_SYSTICK_Config(HAL_RCC_GetHCLKFreq()/1000); /*Configure the Systick / HAL_SYSTICK_CLKSourceConfig(SYSTICK_CLKSOURCE_HCLK); /* SysTick_IRQn interrupt configuration / HAL_NVIC_SetPriority(SysTick_IRQn, 0, 0); } / USER CODE BEGIN 4 / / USER CODE END 4 / /* * @brief This function is executed in case of error occurrence. * @param file: The file name as string. * @param line: The line in file as a number. * @retval None / void _Error_Handler(char file, int line) { /* USER CODE BEGIN Error_Handler_Debug / / User can add his own implementation to report the HAL error return state / while(1) { } / USER CODE END Error_Handler_Debug / } #ifdef USE_FULL_ASSERT /* * @brief Reports the name of the source file and the source line number * where the assert_param error has occurred. * @param file: pointer to the source file name * @param line: assert_param error line source number * @retval None / void assert_failed(uint8_t file, uint32_t line) { /* USER CODE BEGIN 6 / / User can add his own implementation to report the file name and line number, tex: printf("Wrong parameters value: file %s on line %drn", file, line) / / USER CODE END 6 / } #endif / USE_FULL_ASSERT / /* * @} / /* * @} / /********************* (C) COPYRIGHT STMicroelectronics *END OF FILE/ 复制代码 / ****************************************************************************** * @file : usbd_cdc_if.c/// * @version : v2.0_Cube * @brief : Usb device for Virtual Com Port. ****************************************************************************** * This notice applies to any and all portions of this file * that are not between comment pairs USER CODE BEGIN and * USER CODE END. Other portions of this file, whether * inserted by the user or by software development tools * are owned by their respective copyright owners. * * Copyright (c) 2018 STMicroelectronics International N.V. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted, provided that the following conditions are met: * * 1. Redistribution of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * 3. Neither the name of STMicroelectronics nor the names of other * contributors to this software may be used to endorse or promote products * derived from this software without specific written permission. * 4. This software, including modifications and/or derivative works of this * software, must execute solely and exclusively on microcontroller or * microprocessor devices manufactured by or for STMicroelectronics. * 5. Redistribution and use of this software other than as permitted under * this license is void and will automatically terminate your rights under * this license. * * THIS SOFTWARE IS PROVIDED BY STMICROELECTRONICS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS, IMPLIED OR STATUTORY WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A * PARTICULAR PURPOSE AND NON-INFRINGEMENT OF THIRD PARTY INTELLECTUAL PROPERTY * RIGHTS ARE DISCLAIMED TO THE FULLEST EXTENT PERMITTED BY LAW. IN NO EVENT * SHALL STMICROELECTRONICS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * ****************************************************************************** / / Includes ------------------------------------------------------------------/ #include "usbd_cdc_if.h" / USER CODE BEGIN INCLUDE / / USER CODE END INCLUDE / / Private typedef -----------------------------------------------------------/ / Private define ------------------------------------------------------------/ / Private macro -------------------------------------------------------------/ / USER CODE BEGIN PV / / Private variables ---------------------------------------------------------/ / USER CODE END PV / /* @addtogroup STM32_USB_OTG_DEVICE_LIBRARY * @brief Usb device library. * @{ / /* @addtogroup USBD_CDC_IF * @{ / /* @defgroup USBD_CDC_IF_Private_TypesDefinitions USBD_CDC_IF_Private_TypesDefinitions * @brief Private types. * @{ / / USER CODE BEGIN PRIVATE_TYPES / / USER CODE END PRIVATE_TYPES / /* * @} / /* @defgroup USBD_CDC_IF_Private_Defines USBD_CDC_IF_Private_Defines * @brief Private defines. * @{ / / USER CODE BEGIN PRIVATE_DEFINES / / Define size for the receive and transmit buffer over CDC / / It's up to user to redefine and/or remove those define / #define APP_RX_DATA_SIZE 64 #define APP_TX_DATA_SIZE 64 / USER CODE END PRIVATE_DEFINES / /* * @} / /* @defgroup USBD_CDC_IF_Private_Macros USBD_CDC_IF_Private_Macros * @brief Private macros. * @{ / / USER CODE BEGIN PRIVATE_MACRO / / USER CODE END PRIVATE_MACRO / /* * @} / /* @defgroup USBD_CDC_IF_Private_Variables USBD_CDC_IF_Private_Variables * @brief Private variables. * @{ / / Create buffer for reception and transmission / / It's up to user to redefine and/or remove those define / /* Received data over USB are stored in this buffer / uint8_t UserRxBufferFS[APP_RX_DATA_SIZE]; /* Data to send over USB CDC are stored in this buffer / uint8_t UserTxBufferFS[APP_TX_DATA_SIZE]; / USER CODE BEGIN PRIVATE_VARIABLES / // http://www.smilefrog.net/?p=763 "USB-CDC (VCP)“ uint8_t DataLen; // define receive buffer length variable / USER CODE END PRIVATE_VARIABLES / /* * @} / /* @defgroup USBD_CDC_IF_Exported_Variables USBD_CDC_IF_Exported_Variables * @brief Public variables. * @{ / extern USBD_HandleTypeDef hUsbDeviceFS; / USER CODE BEGIN EXPORTED_VARIABLES / / USER CODE END EXPORTED_VARIABLES / /* * @} / /* @defgroup USBD_CDC_IF_Private_FunctionPrototypes USBD_CDC_IF_Private_FunctionPrototypes * @brief Private functions declaration. * @{ / static int8_t CDC_Init_FS(void); static int8_t CDC_DeInit_FS(void); static int8_t CDC_Control_FS(uint8_t cmd, uint8_t pbuf, uint16_t length); static int8_t CDC_Receive_FS(uint8_t* pbuf, uint32_t Len); / USER CODE BEGIN PRIVATE_FUNCTIONS_DECLARATION / / USER CODE END PRIVATE_FUNCTIONS_DECLARATION / /* * @} / USBD_CDC_ItfTypeDef USBD_Interface_fops_FS = { CDC_Init_FS, CDC_DeInit_FS, CDC_Control_FS, CDC_Receive_FS }; / Private functions ---------------------------------------------------------/ /* * @brief Initializes the CDC media low layer over the FS USB IP * @retval USBD_OK if all operations are OK else USBD_FAIL / static int8_t CDC_Init_FS(void) { / USER CODE BEGIN 3 / / Set Application Buffers / USBD_CDC_SetTxBuffer( hUsbDeviceFS, UserTxBufferFS, 0); USBD_CDC_SetRxBuffer( hUsbDeviceFS, UserRxBufferFS); return (USBD_OK); / USER CODE END 3 / } /* * @brief DeInitializes the CDC media low layer * @retval USBD_OK if all operations are OK else USBD_FAIL / static int8_t CDC_DeInit_FS(void) { / USER CODE BEGIN 4 / return (USBD_OK); / USER CODE END 4 / } /* * @brief Manage the CDC class requests * @param cmd: Command code * @param pbuf: Buffer containing command data (request parameters) * @param length: Number of data to be sent (in bytes) * @retval Result of the operation: USBD_OK if all operations are OK else USBD_FAIL / static int8_t CDC_Control_FS(uint8_t cmd, uint8_t pbuf, uint16_t length) { /* USER CODE BEGIN 5 / switch(cmd) { case CDC_SEND_ENCAPSULATED_COMMAND: break; case CDC_GET_ENCAPSULATED_RESPONSE: break; case CDC_SET_COMM_FEATURE: break; case CDC_GET_COMM_FEATURE: break; case CDC_CLEAR_COMM_FEATURE: break; /*****************************************************************************/ / 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). / /*****************************************************************************/ case CDC_SET_LINE_CODING: break; case CDC_GET_LINE_CODING: break; case CDC_SET_CONTROL_LINE_STATE: break; case CDC_SEND_BREAK: break; default: break; } return (USBD_OK); / USER CODE END 5 / } /* * @brief Data received over USB OUT endpoint are sent over CDC interface * through this function. * * @note * This function will block any OUT packet reception on USB endpoint * untill exiting this function. If you exit this function before transfer * is complete on CDC interface (ie. using DMA controller) it will result * in receiving more data while previous ones are still not sent. * * @param Buf: Buffer of data to be received * @param Len: Number of data received (in bytes) * @retval Result of the operation: USBD_OK if all operations are OK else USBD_FAIL / static int8_t CDC_Receive_FS(uint8_t Buf, uint32_t Len) { / USER CODE BEGIN 6 / USBD_CDC_SetRxBuffer( hUsbDeviceFS, Buf[0]); USBD_CDC_ReceivePacket( hUsbDeviceFS); DataLen = Len; //assign receive buffer length, don't edit any other!!! return (USBD_OK); /* USER CODE END 6 / } /* * @brief CDC_Transmit_FS * Data to send over USB IN endpoint are sent over CDC interface * through this function. * @note * * * @param Buf: Buffer of data to be sent * @param Len: Number of data to be sent (in bytes) * @retval USBD_OK if all operations are OK else USBD_FAIL or USBD_BUSY / uint8_t CDC_Transmit_FS(uint8_t Buf, uint16_t Len) { uint8_t result = USBD_OK; /* USER CODE BEGIN 7 / USBD_CDC_HandleTypeDef hcdc = (USBD_CDC_HandleTypeDef)hUsbDeviceFS.pClassData; if (hcdc->TxState != 0){ return USBD_BUSY; } USBD_CDC_SetTxBuffer( hUsbDeviceFS, Buf, Len); result = USBD_CDC_TransmitPacket( hUsbDeviceFS); / USER CODE END 7 / return result; } / USER CODE BEGIN PRIVATE_FUNCTIONS_IMPLEMENTATION / / USER CODE END PRIVATE_FUNCTIONS_IMPLEMENTATION / /* * @} / /* * @} / /********************* (C) COPYRIGHT STMicroelectronics *END OF FILE*/ 复制代码问题1。为什么使用“while（CDC_Transmit_FS（UserRxBufferFS，DataLen））;”？我尝试只使用“CDC_Transmit_FS（UserRxBufferFS，DataLen）”，它似乎也有用。它与下一步“DataLen = 0”（重置DataLen）有关吗？问题2。只有当我在主循环中添加一些延迟（以模拟另一个任务）时，它会丢失消息或只是回转最后一个字。如何避免丢失？请指教！ 0 本主题由 Harmony技术专家于 2024-4-24 15:29 审核通过*
2024-4-24 08:29:20　　评论淘帖0 邀请回答您可以邀请以下用户，快速回答问题 × heks 该类别下有 50 个回答。邀请回答 hgimtk 该类别下有 44 个回答。邀请回答新星之火12138 该类别下有 42 个回答。邀请回答 wang21cj 该类别下有 41 个回答。邀请回答 chm5 该类别下有 40 个回答。邀请回答 hjfjsdgfjdsf 该类别下有 37 个回答。邀请回答 werywer 该类别下有 35 个回答。邀请回答 h1654155957.9520 该类别下有 35 个回答。邀请回答 fdjslkjd 该类别下有 35 个回答。邀请回答 uvysdfydad 该类别下有 35 个回答。邀请回答维生素B2 该类别下有 34 个回答。邀请回答凤毛麟角该类别下有 34 个回答。邀请回答 jenny042 该类别下有 34 个回答。邀请回答 dfzvzs 该类别下有 34 个回答。邀请回答刘洋该类别下有 33 个回答。邀请回答 meihuacg 该类别下有 33 个回答。邀请回答 hfgdzc 该类别下有 33 个回答。邀请回答 ggfvxv 该类别下有 33 个回答。邀请回答河南顺之航该类别下有 32 个回答。邀请回答风来吴山该类别下有 32 个回答。邀请回答举报敷衍作笑谈相关推荐 • STM32虚拟串口遇到的问题有哪些？如何解决？ 603 • NUC980 USB2.0 HighSpeed虚拟串口在Win10通信丢包如何解决？ 218 • NUC980 USB2.0 HighSpeed虚拟串口在Win10通信丢包问题如何解决？ 250 • STM32配置USB为虚拟串口导致设备的串口无法通信 6409 • Openmv如何通过串口接收数据/发送数据与stm32通信? 2958 • 如何利用STM32软件SPI去实现NRF24L01通信呢 1526 • pic单片机485通信问题 4100 • 用labview不能与stm32通信 6505 • u**虚拟串口失败 1549* • stm32f107 485通信 3583 1个回答

答案对人有帮助，有参考价值 0 CDC_Transmit_FS（UserRxBufferFS，DataLen）；一次不一定能够发送成功。因为你发送的时候USB可能处于BUSY等状态。所以采用while（CDC_Transmit_FS（UserRxBufferFS，DataLen））；不断发送，直到发送成功。 DataLen = 0；原作者借用了这个变量来判断已接收到数据---- if(DataLen > 0)----，此处把它设置为0。但不建议这样做。这存在竞争风险。你的第2个问题有可能和这也相关。

2024-4-24 15:05:04 评论举报王强