the windows computer recognized the st-link v2 as universal serial bus instead virtual port

[kevin1971]

Hi.

After firmware upgrade for st-link v2, windows computer recognized the st-link as universal serial bus instead of virtual com port. whenever i try to program to MCU, there is error like a "No target device found".

How can I solve it?

Below image is the device manager to be recognized as Universal serial bus. there is no PORT.

Thank advance.

BR

[Tesla DeLorean]

Ok, but the diode suggests that you expect the ST-LINK to power the 3.3V whereas the expectations for the buffers is that your target powers them. Check the voltage you see on pin 1/2 of the 20-pin header

[kevin1971]

Hi Tesla,

You mean that the target board should provide the power 3.3V to the st-link VDD pin 1/2 of the 20-pin header.

or,Is 3.07V little bit low voltage for flashing?

Thanks

Regards,

[kevin1971]

Hi 

After measuring the voltage of 1/2 of 20-pin header with tester,  the value of voltage is 3.13V.

Thank you.

Regards,

[kevin1971]

Hi,

MCU is STM32L072CZ.

Boot0 is to wired with GND. Now Voltage is 3.25V for VDD : 3.25V, SWDIO, SWCLK, nRST, RST.

Even if I tried to connect with My MCU Board which housed STM32L072CZ, it didn't connect with them.

Please help me.

thank you in advance.

Kevin

[kevin1971]

Hi

Error message is as below if i used the stm32cubeprogrammer.

09:10:59 : UR connection mode is defined with the HWrst reset mode
09:10:59 : ST-LINK SN : 51FF6D066684504828451087
09:10:59 : ST-LINK FW : V2J42S7
09:10:59 : Board : --
09:10:59 : Voltage : 3.25V
09:10:59 : Error: No STM32 target found! If your product embeds Debug Authentication, please perform a discovery using Debug Authentication

Thank you in advance

Kevin

[kevin1971]

Hi

Below is image for ST-Link for nRST and SWCLK when i tried to connect with MCU using STM32Cubeprogrammer.

2 blue channel is nRST, 1 yello channel is SWCLK.

Thank you.

Best Regards,

[kevin1971]

Hi

Below is SWDIO, SWCLK waveform when I tried to connect with MCU using STM32CubeProgrammer.

Thank you.

BR

[kevin1971]

Blue 2 channel and yellow 1 channel are little bit malfunction to measure the voltage.

Thank you.

BR

[Tesla DeLorean]

Is there some issue with the grounding here?

Your diagram here has GND and SWDIO switched. Is the wiring harness correct?

https://community.st.com/t5/stm32-mcus-boards-and-hardware/the-windows-computer-recognized-the-st-link-v2-as-universal/m-p/601176/highlight/true#M15431

[kevin1971]

Hi Tesla,

In first picture, The oscillator is liitle bit malfunction to measure the voltage as you indicated.

However, second picture is good to measure swdio, and swclk waveform.

Thank you.

BR