Question
USBX on STM32H5 CDC - Can't open port.
Hi. Unfortunately, after several days of struggling with USBX, I'm forced to ask for your help. I'm using custom boards with the STM32h503RB and STM32h563VI. I tested the old library according to forum guides – no response when connected to a PC. The closest I've gotten is following the guide for USBX C0. Windows recognizes the CDC device and assigns a COM port, but there's no response when attempting to open the port.
USBX standalone,interrupt enabled, Clock 48MHz, CRS enabled, mempoll size 8*1024, stack size 6*1024
https://www.youtube.com/watch?v=43gcc2dGnxQ
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_USBX_Device_Init();
MX_RAMCFG_Init();
MX_ICACHE_Init();
/* USER CODE BEGIN 2 */
_ux_dcd_stm32_initialize((ULONG)NULL, (ULONG)&hpcd_USB_DRD_FS);
HAL_PCD_Start(&hpcd_USB_DRD_FS);
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
// USBX_Device_Process();
ux_device_stack_tasks_run();
USBD_CDC_ACM_Receive(buffer,BUFFER_SIZE,&received);
HAL_GPIO_TogglePin(LED_GPIO_Port, LED_Pin);
HAL_Delay(500);
if(received!=0){
USBD_CDC_ACM_Transmit(buffer, received, &sent);
received=0;
}
//HAL_GPIO_TogglePin(LED_GPIO_Port, LED_Pin);
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
}
/* USER CODE END 3 */
}/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file ux_device_cdc_acm.c
* @author MCD Application Team
* @brief USBX Device applicative file
******************************************************************************
* @attention
*
* Copyright (c) 2025 STMicroelectronics.
* All rights reserved.
*
* This software is licensed under terms that can be found in the LICENSE file
* in the root directory of this software component.
* If no LICENSE file comes with this software, it is provided AS-IS.
*
******************************************************************************
*/
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "ux_device_cdc_acm.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
/* USER CODE END Includes */
/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
/* USER CODE END PTD */
/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
/* USER CODE END PD */
/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */
/* USER CODE END PM */
/* Private variables ---------------------------------------------------------*/
/* USER CODE BEGIN PV */
UX_SLAVE_CLASS_CDC_ACM *cdc_acm=NULL;
/* Data to send over USB CDC are stored in this buffer */
/* USER CODE END PV */
/* Private function prototypes -----------------------------------------------*/
/* USER CODE BEGIN PFP */
/* USER CODE END PFP */
/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
/* USER CODE END 0 */
/**
* @brief USBD_CDC_ACM_Activate
* This function is called when insertion of a CDC ACM device.
* cdc_acm_instance: Pointer to the cdc acm class instance.
* @retval none
*/
VOID USBD_CDC_ACM_Activate(VOID *cdc_acm_instance)
{
/* USER CODE BEGIN USBD_CDC_ACM_Activate */
UX_PARAMETER_NOT_USED(cdc_acm_instance);
cdc_acm = (UX_SLAVE_CLASS_CDC_ACM*) cdc_acm_instance;
/* USER CODE END USBD_CDC_ACM_Activate */
return;
}
/**
* @brief USBD_CDC_ACM_Deactivate
* This function is called when extraction of a CDC ACM device.
* cdc_acm_instance: Pointer to the cdc acm class instance.
* @retval none
*/
VOID USBD_CDC_ACM_Deactivate(VOID *cdc_acm_instance)
{
/* USER CODE BEGIN USBD_CDC_ACM_Deactivate */
UX_PARAMETER_NOT_USED(cdc_acm_instance);
cdc_acm = UX_NULL;
/* USER CODE END USBD_CDC_ACM_Deactivate */
return;
}
/**
* @brief USBD_CDC_ACM_ParameterChange
* This function is invoked to manage the CDC ACM class requests.
* cdc_acm_instance: Pointer to the cdc acm class instance.
* @retval none
*/
VOID USBD_CDC_ACM_ParameterChange(VOID *cdc_acm_instance)
{
/* USER CODE BEGIN USBD_CDC_ACM_ParameterChange */
UX_PARAMETER_NOT_USED(cdc_acm_instance);
/* USER CODE END USBD_CDC_ACM_ParameterChange */
return;
}
/* USER CODE BEGIN 1 */
uint32_t USBD_CDC_ACM_Transmit(uint8_t* buffer, uint32_t size, uint32_t* sent){
UINT retVal;
if(cdc_acm!=NULL){
do
{
retVal = ux_device_class_cdc_acm_write_run(cdc_acm,buffer,size,sent);
}while(UX_STATE_NEXT != retVal);
return 0;
}else{
return 1;
}
}
uint32_t USBD_CDC_ACM_Receive(uint8_t* buffer, uint32_t size, uint32_t* received){
if(cdc_acm!=NULL){
ux_device_class_cdc_acm_read_run(cdc_acm,buffer,size,received);
return 0;
}else{
return 1;
}
}
/* USER CODE END 1 */void MX_USB_PCD_Init(void)
{
/* USER CODE BEGIN USB_Init 0 */
/* USER CODE END USB_Init 0 */
/* USER CODE BEGIN USB_Init 1 */
/* USER CODE END USB_Init 1 */
hpcd_USB_DRD_FS.Instance = USB_DRD_FS;
hpcd_USB_DRD_FS.Init.dev_endpoints = 8;
hpcd_USB_DRD_FS.Init.speed = USBD_FS_SPEED;
hpcd_USB_DRD_FS.Init.phy_itface = PCD_PHY_EMBEDDED;
hpcd_USB_DRD_FS.Init.Sof_enable = DISABLE;
hpcd_USB_DRD_FS.Init.low_power_enable = DISABLE;
hpcd_USB_DRD_FS.Init.lpm_enable = DISABLE;
hpcd_USB_DRD_FS.Init.battery_charging_enable = DISABLE;
hpcd_USB_DRD_FS.Init.vbus_sensing_enable = DISABLE;
hpcd_USB_DRD_FS.Init.bulk_doublebuffer_enable = DISABLE;
hpcd_USB_DRD_FS.Init.iso_singlebuffer_enable = DISABLE;
if (HAL_PCD_Init(&hpcd_USB_DRD_FS) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN USB_Init 2 */
HAL_PCDEx_PMAConfig(&hpcd_USB_DRD_FS , 0x00 , PCD_SNG_BUF, 0x20);//EP0 OUT
HAL_PCDEx_PMAConfig(&hpcd_USB_DRD_FS , 0x80 , PCD_SNG_BUF, 0x60);//EP0 IN
HAL_PCDEx_PMAConfig(&hpcd_USB_DRD_FS , 0x81 , PCD_SNG_BUF, 0xA0);//EP1 IN
HAL_PCDEx_PMAConfig(&hpcd_USB_DRD_FS , 0x82 , PCD_SNG_BUF, 0xE0);//EP2 IN
HAL_PCDEx_PMAConfig(&hpcd_USB_DRD_FS , 0x03 , PCD_SNG_BUF, 0xF0);//EP3 OUT
/* USER CODE END USB_Init 2 */
}