AnsweredAssumed Answered

ST Link utility 4.2.0 has issues

Question asked by Peter Gibbons on Mar 7, 2018
Latest reply on Mar 14, 2018 by Peter Gibbons

I'm using Windows 8.1, I plug in ST LINK V2 in USB port, but I do not yet connect the other side to a target. I start ST Link utility.

I go to Settings, everything looks good, it shows the serial number and FW version V2J29S7.

I change the Mode to normal, the OK button becomes grayed out, so I have no other choice but to hit cancel.

The settings window closes, I open settings again. Now it is saying USB Communication Error! I hit refresh, doesn't make a difference. Also under serial number it now says "Old ST-LINK firmware/ST-LINK already used".


Next I unplug the ST LINK V2, then click on Refresh. Now it says "No ST-LINK detected !", I plug ST LINK V2 back in.

I click refresh and now it looks all correct again (as stated above). I change Mode back to 'connect under reset', and now it is saying the USB communication error again.


My problem is that I have issues connecting to a target but I'm having issues even without the target, so I don't know if the problem is with my target or with the ST Link utility software. Does this sound like normal behavior or is my ST Link V2 broken (it's brand new)? Can I download an older version of ST Link utilities?


Otherwise the laptop runs great, I have no other problems, all my USB ports are working great. Also in device manager, ST Link V2 shows up normal. It shows up under 'universal serial bus device' as 'STM32 STLink'. Says it's working normal and driver version is


Even after ST Link utility says there is a usb communication error, in device manager, it's still showing up normal. Also noticed that ST Link utilities sometimes becomes unresponsive for about 10 seconds.


Please help me as I'm currently unable to continue development and it was Semtech that recommended to our company that we should switch over to ST microcontrollers because before this we were using TI and also PIC and had no issues with either of those.