2022-07-05 05:13 AM
Hi!
I got my first programmer like this:
It broke after some time of using. I thought that the reason of it breaking was that i used 3.3V pin to power my board sometimes. So, some day my PC stopped seeing it and I got error "device descriptor request failed". Of course I tried uinstalling drivers and installing them again but nothing helped.
So, with the second one I stopped using power pin, because I thought it caused the breakage. But today it broke too. I tried to get working again, but I failed. I tried same thing with drivers, it didnt helped. Then i found this: https://electronics.stackexchange.com/questions/477166/st-link-v2-repairing-issue
and connected my st link v2 to st link I got on stmf4-discovery board. I succeeded in programming it, but afterwards it still shows as uknown device on my computer.
What is the reason for those things to keep breaking?
How to fix them?
I ordered a new one, but I would really like to know how to prevent such a situation again.
Thanks!
2022-07-05 06:26 AM
"What is the reason for those things to keep breaking?"
They're cheap - what did you expect?
If you want something with warranty & support, buy a genuine ST-Link ...
2022-07-05 06:47 AM
Perhaps approach the problem as an Electronics Engineer rather than a Software Engineer?
Check how well the connectors are soldered, and the continuity of the D+/- pins on the USB interface, especially where the descriptors get to be problematic.
Perhaps generate a rough schematic of the pod.
Looking at powering, regulators, capacitors, etc.
Current shouldn't be very high, but components might be of low quality, or of inexact values.
Apt to lack protection components more expensive designs might include. ie ESD or buffers on the JTAG signals.
Use good cables, avoid hubs and docking stations.
2022-07-05 07:03 AM
@Community member "Apt to lack protection components more expensive designs might include. ie ESD or buffers on the JTAG signals."
+1
Also, more expensive models (including the standalone ST-Link/V2) support & auto-detect a range of target voltages - but I've only seen Chinese clones fixed at 3.3V.
Another thing is that there's no standard pinout, and it does vary!! :o
So, if you've got more than one, it's possible that they have different pinouts - which could cause damage...
2022-07-05 07:07 AM
Here's an example - look carefully at the pinout legends on these two:
2022-07-05 09:05 PM
It's not like I didn't expect that, but I wonder is there something that I do wrong or it's just the charm of the chinese clone.
2022-07-05 09:07 PM
Yes, that definitly is the big problem. I tried to find the schematic of my clone but I think that is not possible.
2022-07-05 09:09 PM
Thanks for the advice. I tried measuring the board yesterday but I think that maybe I could miss something.
So basically, the real difference between original and clone is the quality of components, and the ones used here just stop functioning, is that it?
2022-07-06 01:05 AM
Not just the quality of the components: it's also a cut-down design.
There is no guarantee of consistency/continuity - even when buying from apparently the same source.
It's essentially undocumented and unsupported.
You gets what you pays for!