"no device found" with external target on Nucleo-ST-Link
Hi,
I just wanted to debug my STM32L412 custom board using my Nucleo-F767 as ST-Link just as I did many times before.
But this time it won't work! Connecting to the board always yields an
Error in initializing ST-LINK device.
Reason: No device found on target.Connecting to the Nucleo-board works just fine.
Connecting to the custom board worked fine this morning. I could connect to 3 different custom boards, but all of a sudden it stopped working. Same phenomena last Friday. It initially worked well, but after a short while, impossible to connect. Some of the boards, I have used the ST-Link with very often before for much debugging. So the schematic and layout is fine and it worked for many boards of that kind for many weeks/months.
The ST-Link-STM32F103 is getting slightly warm, you can just feel it. But I never paid attention, so that might be normal...
BOOT0 is grounded, nRESET is high and gets pulled low by ST-Link.
I see activity on SCLK and SDIO although the clock does not look very nice to me. But again, since all worked well before, I never checked the signals.
Attached are two "screenshots" from the scope.
Channel 1 = nRESET
Channel 2 = SDIO
Channel 3 = SCLK
01 is the whole "data packet" being transmitted, 02 is a close up to show the strange clock signal.
I also tried STM32CubeProgrammer - no connection possible there as well.
I tried updating ST-Link firmware, downgrading to another version, and back up... reinstall drivers, updating CubeProg from 2.4.0 to 2.5.0, nothing worked so far.
This is a bit frustrating since now I don't knw where to look further...
any ideas?
all help very welcome!
Cheers,
Bob