USB VCP CDC pin connections

[Raahul Jagannathan]

Posted on July 05, 2018 at 08:00

Hi, 

I am trying to interface my SSTM32F446RE with the computer using USB VCP CDC interface. I have configured it using cubeMX and it is set up perfectly. Do i have to connect anything to USB_OTG_FS_DM 

USB_OTG_FS_DP Pins? Also what is the Baud rate that I have to set in the terminal?

[Raahul Jagannathan]

Posted on July 05, 2018 at 08:18

The only port I see in device manager is the STMicroelectronics STLink Virtual COM Port. I do not see the STMicroelectronics Virtual COM Port (which is the one others see and use in their videos). How do I see that?

[Cyril FENARD]

Posted on July 05, 2018 at 10:57

Hi

f20160814

,

What you are reporting is the normal behavior.

Note that STM32F446RE provides Advanced connectivity

- USB 2.0 full-speed device/host/OTG controller with on-chip PHY

- USB 2.0 high-speed/full-speed device/host/OTG controller with dedicated DMA, on-chip full-speed PHY and ULPI

- Dedicated USB power rail enabling on-chip PHYs operation throughout the entire MCU power supply range

The NUCLEO-L446RE does not have USB connector other that ST-LINK.

You can move to other product of this family, a STM32F429I-DISC1 can do the job. MCU Selector of CubeMx can help you make your choice.

Hoping it clarifies.

Regards.

Cyril.

[Raahul Jagannathan]

Posted on July 05, 2018 at 11:47

I am having problems getting any response in the serial terminal.

I have interfaced an STM32F446RE in USB-CDC mode. I have made it device only, I set the middleware to CDC, and I set the clock appropriately too. I also added the change to CDC_Transmit_FS function. When I try to use CDC_Transmit_FS in a loop to try and print something in the terminal window (hyperterminal is used), even after giving large delays, nothing is getting printed on the terminal. The drivers have also been installed and in device manager I see, STMicroelectronics STLink Virtual Com port. I changed the size of stack and heap as well, and I have changed the packet sizes to 64 too.