2018-12-17 08:45 AM
I'm feeling really stupid about this. We were unable to debug in our circuit, so to check, we have a standalone STM32L021D4Px, mounted to a solderless breadboard. 3.3V is connected to Pin 14, ground to pins 9 and 1, NRST to pin 4, SWDIO to pin 13 and SWCLK to pin 14.
The debugger does not see the target. The Keil IDE sees the ST-LINK/V2 OK.
Clearly I'm missing something. Can anybody tell me what I'm missing?
Thanks
Solved! Go to Solution.
2018-12-18 06:58 AM
Odd, the firmware can be down graded
2018-12-18 09:28 AM
2018-12-18 10:05 AM
This is v2.27.15
https://drive.google.com/open?id=0B7OY5pub_GfITE82bnBza2RCbEE
2018-12-18 10:21 AM
2018-12-18 11:13 AM
DOH! I knew it was going to embarrass me when the truth became evident.
We have the isolated version of the ST-LINK/V2. Of the 9 GND pins on the connector, five of them cannot be used for GND because they are disconnected or otherwise purposed.
I moved the GND signal from Pin 4 to Pin 20 and voila!
Thanks, Clive. You're the balls.
2018-12-18 11:33 AM
I archive stuff, it provides historical context to issues, and allows problems to be regression tested. One of the policies the people I work with have is to archive design documents, so design decisions can be reviewed with contemporary documentation.