USB virtualCOM with STM32F769 Discovery

[Omar Suárez]

Posted on March 13, 2017 at 15:09

Hi,

I am beginning with STM32 MCUs, more concretely with STM32F769NI. I have a STM32F769 Discovery board to make tests. My first attempt was to use the USB from the board to communicate with a PC.

Looking for info about USB OTG I came across the virtualCOM that enables USB to communicate as serial ports and the USB CDC Class Device that it is used for this task.

I have tried to follow the application example for de EVAL board called CDC_Standalone, that is inside the STM32cubeF7 but I am a bit lost. I am not sure whether this is the app I need to implement. I can't find any function to transmit or receive data to the virtualCOM.

Moreover, reading the board documentation it is said that the ST-LINK Embedded debugger can works as virtualCOM, so I don't understand whether  it is  possible to configure the USB OTG connection to work as virtualCOM also or you need to work with the ST-LINK directly (there are a USB connector for ST-LINK and other one for the USB OTG).

Anyon can help me with this topic?

Thanks in advanced,

Omar

#usb-otg #stm32f7 #usb-cdc #virtual-com

[Tesla DeLorean]

Posted on March 13, 2017 at 15:57

The ST-LINK chip provides a Virtual COM port as part of its implementation, the STM32F7 communicates with this via a physical USART. In this case USART1 via PA9 and PA10

http://www.st.com/content/ccc/resource/technical/document/user_manual/group0/7c/c9/c0/5f/4e/9b/44/eb/DM00276557/files/DM00276557.pdf/jcr:content/translations/en.DM00276557.pdf

 

[Omar Suárez]

Posted on March 13, 2017 at 18:16

Thanks for the reply.

The fact is that I want to use the USB OTG device instead the ST-LINK, because in my application I will need to use the virtualCOM and ST-LINK won't be available.

[Dome Bova]

Posted on March 19, 2018 at 09:33

It seems that in the discovery doc there's an error: it says USART3, but pins A9,A10 are connected to 769 USART1 ..

[Imen.D]

Posted on March 22, 2018 at 14:32

Hello

dobova86

,

You are right about the

typoin UM2033:

VCP usesUSART1and not USART3.

This is known typo and the modification will be published in the next

User manual UM2033 revision (rev 3) which should be available shortly.

Best Regards,

Imen

[Imen.D]

Posted on April 26, 2018 at 17:05

Hello,

A new release of

UM2033 (Rev 3) 

is pusblished and available with correction of this typo.

Best Regards,

Imen