How can use st-link as a uart for stm32f429 discovery board?

[KISHAN PATEL1]

Posted on January 11, 2018 at 10:48

I want to use UART with on board.So,is it possible to use st-link as a uart communication.

If yes,then how and if not then any other option to communicate with uart by using on board circuit.

Thanks & Regards,

Kishan Patel.

#stm32f429disc1 #st-link #uart

[Bogdan Golab]

Posted on January 12, 2018 at 07:22

You need the latest version of the board (coded DISC1?). The ST-link version in this newest board is able to bridge target MCU UART to the emulated by the USB drivers of the st-link (on the PC).

Then you enable the uart on the target MCU - if in cubemx it's really simple and use hal_uart_transmit/receive function to send a piece of data toward pc. On the pc side the usb drivers will emulate COMx and the app using this link (through the emulated COMx) should have this COMx configured.

I use this concept a lot on different nucleo / disco board. Sadly have an old 429 board and in this case I need an extra uart/usb converter

[Bogdan Golab]

Posted on January 12, 2018 at 07:23

http://www.st.com/en/evaluation-tools/32f429idiscovery.html

 

• STM32F429ZIT6 microcontroller featuring 2 Mbytes of Flash memory, 256 Kbytes of RAM in an LQFP144 package
• On-board ST-LINK/V2 on STM32F429I-DISCO (old order code) or ST-LINK/V2-B on STM32F429I-DISC1 (new order code)
• mbedâ„¢

  -enabled (see

  https://community.st.com/external-link.jspa?url=http%3A%2F%2Fmbed.org

  ) with the new order code only

• USB functions:
  • Debug port
  • Virtual COM port (with new order code only)

[Bogdan Golab]

Posted on January 12, 2018 at 07:25

CP configuration

The ST-LINK/V2-B on STM32F429I-DISC1 supports virtual COM port (VCP) on U2 pin 12

(ST-LINK_TX) and U2 pin 13 (ST-LINK_RX), wh

ich are connected to the STM32F429 target

STM32 USART1 (PA9, PA10) for Mbed support, thanks to the SB11 and SB15 solder

bridges.

The SB11 (PA9) and SB15 (PA10) default configurations for 32F429IDISCOVERY and

STM32F429I-DISC1 are given in

Table 5: Solder bridges

.

as per:

http://www.st.com/resource/en/user_manual/dm00093903.pdf

 

[KISHAN PATEL1]

Posted on January 12, 2018 at 11:48

Thank you guys for replies.

            I have checked connection of uart pins and its connected as you told.(PA9 with SB11 and PA10 with SB15).

I can use uart communication by connecting external uart with PA9 and PA10 pins.

But when i tried to use directly USB ST-LINK,its not working.

So,if i want to use USB st-link directly.Any hardware connection(jumper) or software configuration required?.

Thanks in advanced.

[Bogdan Golab]

Posted on January 12, 2018 at 12:34

I have never used it for this board (usually use nucleo and stm32l476) so I do not know. From the board manual it should be ready (mbed ready as well).

Could you detail what is not working? How did you test it? Is the new COMx available in the Windows Device Manager? Did yo try to connect a terminal app?

[Tesla DeLorean]

Posted on January 12, 2018 at 13:05

Only the DISC1 model of the board has a suitable ST-LINK that supports the VCP mode.

[KISHAN PATEL1]

Posted on January 12, 2018 at 14:30

Hello guys,

            Finally,i can use ST-LINK as a serial communication.

I have changed nothing.Just retried and its working properly.

Thanks guys.

[Bogdan Golab]

Posted on January 12, 2018 at 14:55

It's rather stable solution  - VCOM - I use it for years

[KISHAN PATEL1]

Posted on January 12, 2018 at 14:59

Yes.There is no need of external usb to uart converter.