I have STM32F407VET6 black and i am trying to setup serial communication with this device

[SRath.4]

In my laptop device manager this device only shows up as stm32 bootloader and not as virtual com port or anything else to communicate , Can anyone help please! as trhere's not much help available regarding this same controller,

[Peter BENSCH]

Welcome, @SRath.4​, to the community!

You surely mean the board STM32 F4VE from STM32-base?

Well, even if the STMicroelectronics logo is used illegally there, it is not a board from STMicroelectronics. In this respect, the first point of contact would be the manufacturer of this board. But it is no wonder that this company is misusing the logo, because it also produces illegal counterfeits of the ST-LINK debuggers, which usually also contain counterfeit STM32s.

But after a cursory glance at the circuitry of this board, where I could already see the same systematic errors as with the infamous Blue Pill, it was obvious that there is only the STM32F407VET6. By the way, it remains to be hoped and checked that this is an original STM32, as counterfeits were also very often used with the Black Pill.

In any case, apart from the STM32, there is no debug interface as, for example, the well-known and genuine NUCLEO boards from STMicroelectronics have. However, this would require that you see a virtual COM port in your host computer, for example.

I wish you good luck trying to get support from stm32-base.org.

Regards

/Peter

[SRath.4]

There's no any help available on stm32-base, can you help me setup communication ?

[Peter BENSCH]

Since it is not certain that it is a genuine device from STMicroelectronics, I cannot really help.

However, you could connect an ST-LINK/V2 or ST-LINK/V3MINIE or ST-LINK/V3SET to the JTAG/SWD connector P1, which should allow you to connect.

Good luck!

/Peter

[SRath.4]

The board i have is STM32F407 and official st webpage provides documentation for this, so i has to be official board only. (official web:STM32F407/417 - PDF Documentation)

[Tesla DeLorean]

That's a chip, it could be on all manner of boards. Review documentation.

​

Did Peter identify the board you own? Attach picture.

​

T​hat board.looks to have a 20 pin JTAG header, if so you can use ST-LINK to download and debug.

[SRath.4]

yes, the board has 20 pin JTAG header, but is there any other way other that JTAG?

The issue is that when i connect bourd using USB it shows as STM32 BOOTLOADER device under device manager so how can i change it to COM or something else?

[Peter BENSCH]

As I said and Tesla confirmed: if you want to have a COM port, you should connect one of the suggested ST-LINK. The term JTAG is just a general term for the connector, the ST-LINK connects to the target via SWD over this connector.

[SRath.4]

Ok, thank you for this help, SO can i use VCP while implementing this device in practical use, like to send some command from laptop or PC and receive data collected by controller back to pc or is there any other method to do that because device won't run normally in DFU mode, right?

[Peter BENSCH]

I have already mentioned it a few times: here, no one can make a safe statement for the chip on a device from a board manufacturer until it is certain that the chip is actually from STMicroelectronics.

However, I must clarify one of my statements: an ST-LINK alone is no guarantee for a functioning VCP. A VCP consists of two things: on the one hand, on the target MCU side, a UART that is connected to the ST-LINK, and on the other hand, the ST-LINK that puts this as a data stream on the USB channel in addition to the other USB communication.

On NUCLEO boards, there is a hardware connection from a UART of the respective MCU to the MCU of the ST-LINK.

So if you just connect an ST-LINK, you only have the SWD connection without UART and therefore without VCP.

A VCP is not possible with an ST-LINK/V2 because its UART is not (easily) accessible.

An ST-LINK/V2-1, which is included on many NUCLEO-64 and some NUCLEO-144, has an additional connector where the UART of the ST-LINK MCU is accessible and where a UART of your board can be connected.

An ST-LINK/V3MINIE or ST-LINK/V3SET also has a UART port for the respective target.

Assuming that the chip on your board is indeed from STMicroelectronics, then you should indeed be able to get a VCP to the host with one of the ST-LINK mentioned above, via which data can be transferred serially to and from the host.

However, this also requires the appropriate programming of the U(S)ART, because - to use a comparison - the existence of a road does not guarantee coordinated bus traffic.

Regards

/Peter

[SRath.4]

Can you please provide me any documentation or literature with demo for connection of stlink-v2 and its communication protocols with examples?

[Tesla DeLorean]

If you need all if this perhaps you should start with a NUCLEO board? Say one of the 144 pin series.​

[SRath.4]

Hello there,

In your previous suggestion as "on the target MCU side, a UART that is connected to the ST-LINK" does that mean only UART with ST LINK is the solution for send and read process in between pc and board, Or If I connect ST-LINK V2 to the SWD of the board, would that work for read and send between pc and board? or UART is the only way with ST LINK?

[Peter BENSCH]

One of the mentioned ST-LINK (no ST-LINK/V2) would be able to pass a hardware UART of the target as VCP to the host via USB.

There are of course other possibilities, e.g. USB CDC (communication device class), with which you can realise the VCP directly via the USB port without hardware UART (works both via USB-FS and USB-HS). If you want suggestions on how to set this up, just search for "stm32 vcp cdc" using your favourite search engine.

Regards

/Peter

[SRath.4]

OK, I'll try this,

I am encountering a problem with my board: when I connect it to my laptop via mini USB, it does not appear under any connected devices in the Device Manager. Specifically, it does not show up as anything under USB, COM port, or mass storage. However, when I connect it in DFU mode, it appears as STM32 bootloader. What should I do to make it appear under COM or USB devices? Right now, it doesn't seem to be showing up as connected to anything at all.