STM32F4 Debugging anyone?

Electronics
1

I am wondering if anyone would want to take a crack at reviving this STM32F4 based board. It is from a Flashforge Dreamer 3d printer. It seems that it is a common problem among these printers to receive a firmware update and become “bricked”

Having had some experience with Arduino, STM Discover boards, and Jtagging a Cricut cutting matchine (Atmel chip), I figured there might be a way to connect a debugger to the board.

I’m wondering if there are any ISP ports or some way to flash a good firmware .bin file?

flashforgedreamerboard1.jpg4160×2340 2.25 MB

corrected pinout:

flashforgedreamerboard2b.jpg2468×2340 1.26 MB

2

That micro has SWD (serial-wire debug); TMS/SWDIO is on TQFP pin 105 (PA13) and TCK/SWCLK is on TQFP pin 109 (PA14).

Using OpenOCD and a SWD-capable dongle (can be just a FTDI break-out board), you should be able to erase the device’s flash and re-program a good image.

http://www.allaboutcircuits.com/technical-articles/getting-started-with-openocd-using-ft2232h-adapter-for-swd-debugging/

3

Hmm. Sorry, I misspoke. I have the Nucleo boards. Which has a tear off debugger board…Think I can hack this for the job?

http://www.st.com/en/evaluation-tools/nucleo-f411re.html

4

Yes, the break-off debugger portion of the F144RE has the firmware to be a CMSIS-DAP debugger, which can talk SWD to the chip on the larger board.

(edit: Make sure voltage levels are the same. Measure TMS/SWDIO on both boards to make sure they are 3.3v when high)

5

Thanks! I’m reading the manual, finally found it. Thanks for the confirmation.

6

Ok so I read the pdf and am a bit vague on NRST and SWO pins. It’s conspicuous that they created a 3 pin header for SWD for GND, SWDIO and SWCLK. Yet there are the two extras NRST and SWO. SWO seems optional because its used for debugging, which I’m not going to do. Thoughts?

7

UGh. Getting no where. My weller soldering station is dead and I need to put a header on 3.3v. Think you’d mind helping me at the space with this some time?

8

Bring it by my shop in Highland Village if you want. I have my solder station on and am working on some arcade game boards for customers tonight and tomorrow.

I’ll be out there for a couple more hours tonight. :slight_smile:

9

You don’t strictly need NRST (reset, active-low) to load code. The SWO line isn’t important, since all functions can be done with SWDIO and SWDCLK.

10

Cool beans. I sent you a PM

11

Thanks for the info Zach.

12

I’m thinking this chip really is dead. Just applying 3.3v and GND the chip
is getting warm to the touch. STLink utility wont erase it. The story on
this thing is that Flashforge sent out a firmware update that was for a
different revision to the board and it bricked a bunch of printers. The
only recourse the owners had was to buy a new motherboard ($110). Seems
fishy but it is what it is. I was hopeful that I could revive it.

Cheers,
Mark

13

Yeah, that doesn’t sound good. Oh well, at least its a cheap fix.

14

That is strange. A flash update shouldn’t destroy the chip.

15

So, I’m fairly confident that I have the STLink board connected correctly to the target board with 3.3v power. But it still doesn’t link to the chip.

16

If you have all the firmware you need, you might just try swapping out and soldering in a new one.

17

I’d measure current consumption before de-soldering the old one, then after it’s been pulled out of circuit. If the current consumption is nearly the same, the microcontroller wasn’t your problem. Putting a new one back before checking all the power rails is a good way to toast the new one, too.

Check all VDD lines for proper voltages, etc.

1 Like
18

Yeah that’s 144 pins of SMD fun right there…

19

Hot air + paste = 10 minutes if there are no parts on the back.

20

Should be fun. Think I’ll practice on a non critical scrap board lol