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Trouble with USB connenction


after I install mini gerbil into my K40 everything work nice, but after first one hour of cutting gebil has been disconected and Windows show "usb device not recognized".   I've tried different cables and computers, but always with the same or no result.


Hi, It seems either an issue with the board or Windows which we should be able to trace.

When the Gerbil board is powered and not connected to a PC, does the little led (led2 near the USB connector) on the board flashes (heart beat)? If not then the controller is not running and we need to replace it.

Assume it's the board, can you replicate the issue or is it permanent? If you can replicate the issue, can you move the jumper bridge JP1 from the '5vExt' position to '5vUSB' position on the board and test again?

Assuming it's Windows, connect the usb cable and power the gerbil board with the jumper bridge on the board set to just 5vUSB (leave power on K40 off) and test again to see if you can see the USB device.  Let us know the findings and we take it from there.

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Cheers, Paul awesome.tech

Hi, when board is not connectet, led flashes. When bridge was replaced to power via USB, it flashes too.


Okay that means the board is functioning. Next is to see what Windows version you are using. Win10 will install the driver automatically but older windows might need a legacy driver.

The legacy driver can be downloaded from here https://www.st.com/en/development-tools/stsw-stm32102.html

Please let us know and we figure out the next step. If you're on Win10 then you might want to open the device manager and see what the windows system says. (error message or driver issue). In the 'Type here to search' box in win10, type 'device manager' and look under com ports.

cheers, Paul

Cheers, Paul awesome.tech

I using Win 8 and driver I tried install, it worked aproximately one hour only, after that I tried reinstall driver, or install on another PC with Win 7 or XP, nothing worked.

We also tried buy new miniUSB cable, but our tip is bad connector on board.

Hi Libor, best is to return the board and I will check it and replace it if defect.

Cheers, Paul

Cheers, Paul awesome.tech


can you sen me adress to l.masik@volny.cz?



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