Why doesn't the Nucleo F767 board ST-LINK work when connected via a usb hub?

dhaselwood · ‎2019-06-19

A brand new Nucleo F767ZI. Plug in USB cable to the ST-LINK usb connection on the board. The Red "com" led comes on steady for about 1/2 sec then begins blinking several times per sec. No other LEDs on. I find the not/pwrEN line from the ST-LINK processor high. Suspecting that ST-LINK is not happy so I try plugging into various hubs and the PC.

I find that the board only works when plugged directly into the PC. I have several different usb hubs, several externally powered and it works with none of them. However, 'lsusb' (Ubuntu 16.04 LTS) shows it is recognized regardless of where it is plugged in--

STMicroelectronics ST-LINK/V2.1 (Nucleo-F103RB)

Also, it is a bit puzzling why it reports (Nucleo-F103RB). I would have expected Nucleo-F767ZI.

If the Nucleo F767 board won't work via a usb hub, it would be most helpful if the Nucleo User Manual had a few words about troubleshooting. At first I was a bit worried it was a bad board as I have three DiscoveryF3 boards and one was DOA (it wasn't worth troubleshooting, but I suspect something in the power).

Uwe Bonnes · ‎2019-06-20

Is your hub powered? I guess not. Try a powered hub. For a test, remove all other devices from the hub so that only load is the nucleo.

dhaselwood · ‎2019-06-20

This morning I discovered that it worked via both powered and unpowered hubs. Further experimenting points to a problem of using ST-LINK/V2 and ST-LINK/V2.1 devices. I haven't sorted out all the combinations but it has to do with having used a DiscoveryF4 (ST-LINK/V2) and NucleoF767 (ST-LINK/V2.1) (via separate hubs) and the last one used sometimes precludes the other. However, when the DiscoveryF4 (ST-LINK/V2) was the last one used, e.g. used meaning openocd/telenet debugger executed, then closed, the Nucleo F767 will not connect via any hub, but it will connect when plugged directly into the PC.

Net--the problem stems from using devices with different ST-LINK versions even though one device has been unplugged "'something" remembers or doesn't update when the other device is plugged in.

Uwe Bonnes · ‎2019-06-24

Did you also upgrade all fiirewares to recent?

dhaselwood · ‎2019-06-24

Thanks for the response. I have not upgraded the ST-LINK firmware on any of my Discovery or Nucleo boards. I'll look into it.