Remove red and black for usb cable when using the stm32 with a power pack

[psmmacker]

Has anyone  thought  of a usb that only send data 

The reasons why the stm32 discovery gobe nosie is because

If the pc gnd is connected to the stm discovery and the power pack

Interference issue can happen as the gnd os feed back to the computer 

I would rewire the usb or bry a cable with no gnd or 5volts just pure

Pc data only one white and green no gnd - black or 5volt + red

Thanks paul

[psmmacker]

Tryit dont work but what if we powered the usb 5volts  and - from the power pack form the mini usb port and have a data + and - go to the pc usb  only

Dont know if that would help with interference 

Thanks

Paul