Switched my STM32F4 discovery and now Virtual Com port is not working

[Patrick Morwald]

Posted on February 05, 2018 at 17:00

Hi,

i swapped my first STM32F407G-DISC1 discovery board for a new one and now the ST-Link onboard doesnt show up as a virtual com port in Windows 10 anymore. 

I flashed the St-Link with the new firmware, it runs V2.J30.S0 STM32 Debugger now.

I also installed the current Windows driver from 

http://www.st.com/content/st_com/en/products/development-tools/software-development-tools/stm32-software-development-tools/stm32-utilities/stsw-link009.html

.

Now i read the DISCOVERY boards dont all have the virtual com, but in

http://www.st.com/en/evaluation-tools/stm32f4discovery.html

it says that my order code should have it (on my PCB is a silk print next to the USB connector that says 'STM32F407G-DISC1).

Can it be that the silkscreen board code doesnt correspond to the 'order code' which is mentioned on the above website?

Please help since i really need the virtual COM port.

Patrick

#st-link-v2-1 #stm32f746-discovery #stm32f4

[Bogdan Golab]

Posted on February 05, 2018 at 17:06

Run St-link utility to see firmware version. v2-1 is required (in this case v2-B

[Bogdan Golab]

Posted on February 05, 2018 at 17:13

The latest (DISC1) version shall have the st-link based on STM32F103CBT6 - the old  - STM32F103C8T6. Flash size matters  - bigger flash is needed for the ST-link/v2-B where the VCOM is implemented

[Patrick Morwald]

Posted on February 12, 2018 at 10:19

Hi,

i have two boards, one of them doesnt instantiate the VCOM port, it has:

10:14:12 : ST-LINK SN : 066FFF535748775187133407

10:14:12 : ST-LINK Firmware version : V2J30S0

and the other board does instantiate it and has:

10:17:19 : ST-LINK SN : 066BFF3731324B4D43205239

10:17:19 : ST-LINK Firmware version : V2J25M14

Both boards are labeled MB997D / STM32F407G-DISC1 on the silkscreen and St-Link shows RevisionID: Rev 2.0 for both of them.

Can i upgrade the firmware of the non-working one to the firmware 

V2J25M14 or does it not fit the flash size?

[Bogdan Golab]

Posted on February 12, 2018 at 10:28

The standard way is to run  ST-LINK Utility and see after connecting to the target if the red message appears in the log - it will be stated if the upgrade is possible.

Just run the utility to see the checking results. Then you can upgrade the firmware from the same utility  - 'ST-LINK->Firmware Update' (sometimes you need to re-plug the USB cable when the tools complains about the connectivity).

If this does not help (I mean the ST-LINK Utility) more investigation will be required.

[Tesla DeLorean]

Posted on February 05, 2018 at 17:26

Are they different board revisions?

Pretty sure the MB997D instantiates the VCP, but it's not physically wired up to anything.

[Bogdan Golab]

Posted on February 05, 2018 at 17:37

Are you sure that MB997D applies to STMF429-DISC1?

Isn't it STM32F407G-DISC1 which has the MB997D?

[Bogdan Golab]

Posted on February 05, 2018 at 17:40

Sorry  - I have noticed that the boards is really F407