Request for help with USB CDC interface
(STM32F401 Can not open Virtual Port)
I want to send data at about 5Mbit/s from my Nucleo board to Matlab using the USB interface with the CDC protocol. I have now managed to get the PC to recognize a "Serial USB device" on COM6. But I am not able to open the port, neither with Matlab nor with a terminal program (HTerm). What can I do to use the virtual COM port?
With the same setup I could already use the HID protocol. A mouse pointer example for deflecting the mouse pointer in X-direction ran successfully.
I would be very grateful if you could help me to use the virtual interface!
To the info:
I use the Nucleo F401RE board. The PC runs with Windows 10.
As tool chain I use:
CubeMX 5.5.0 and
SW4STM32 version Neon.3 release 4.6.3.
USB is connected as follows:
D+ via a 1.5k pull up resistor to 3.3V of the Nucleo and connected to PA12
D- connected with PA11
The USB GND is connected to the Nucleo GND
The USB VCC (+5V) is not connected
In CubeMX the following is set:
* Connectivity:
USB_OTG_FS / Device_Only
"Activate_SOF" and "Activate_VBUS" are inactive.
* Middleware: USB_Device / Communication Device Class (Virtual Port Com)
* In the Project I increased the minimum heap size from 0x100 to 0x800.
In the main.c program the following 3 additions are made:
1)
/* Private includes --------*/
/* USER CODE BEGIN Includes */
#include "usbd_cdc_if.h"
2)
/* USER CODE BEGIN 2 */
HAL_Delay(1000);
uint8_t buffer[] = "Hallo, Welt!\r\n";
3)
/* USER CODE BEGIN WHILE */
while (1)
{
CDC_Transmit_FS(buffer, sizeof(buffer));
HAL_Delay(1000);
HAL_GPIO_TogglePin(LD2_GPIO_Port,LD2_Pin);
