Bricked STM32F105RB

I am a heavy user of STM32F105RB/RC, but I have not used it much with SW4STM32 before. SW4STM32 (System Workbench for STM32) or ac6wb as it also is called is based on eclipse and uses OpenOCD to connect to the MCU’s Serial debugger. A few days ago while testing CANUSB I noticed problems. First on one MCU, then on a 2nd, 3rd, 4rth and 5th as I just continued bricking MCU’s to rule out that it was the batch.

The library and code here is generated with CubeMX, so I am not sure if it is the generated code, OpenOCD or SW4STM32 that trigger the problem.

I just brought the original MCU back simply by erasing flash with STM32 ST-Link Utility. It worked fine with CoIDE, but as soon as I try SW4STM32 OpenOCD will brick it. Some times it works fine a few times before it suddenly break and I need to bring it back with STM32 ST-Link Utility.

Adding to the story – I downloaded the code generated by CubeMX manually and the same happened. OpenOCD ir SW4STM32 do have a bug because it is not capable of programming the MCU while CoIDE has no problems. But, even STM32 ST-Link Utility cannot connect after code is started, so I need to do a connect under reset – meaning the problem here is the code generated from CubeMX.

This is not the first time CubeMX hits me in the face with a non-mature code example. The tool is great, but I am not able to trust it’s code at precent.

I tried to generate a test project from EmBitz as well, but that uses old libraries for a start and it don’t even compile as it miss the main header file. It just proves to me that I need to manually assemble the HAL myself file for file. I would like to use the newer CubeMX, but I do question their maturity Level.

It also raises a question wherever I should just move on to STM32F405RG. F105 is a real good MCU, but it is less supported than F103 and F405. It cost 50% of a F405, but it is nothing a F105 does that F405 can’t do better. In schematics it is only 2 capacitors that differ the design and they are drop in replacement of each-other on electric levels – obviously F105 have a few less capabilities than F405. I am not ready to give in on F105 just yet, but I am reaching a point where the added cost has to be weighted against time usage and support. And the only argument so far in favor of STM32F105 is that it cost a bit less than F405.

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