Blackpill one pin can't be set

[mogplus88]

I have a problem with one pin, A11, on my Blackpill. When I run the command:
x = Pin('A11', Pin.IN, Pin.PULL_UP)
Thonny crashes with this error:
PROBLEM IN THONNY'S BACK-END: Exception while handling 'execute_source' (ConnectionError: device reports readiness to read but returned no data (device disconnected or multiple access on port?)).
To get the board working again I have to press the reset button on the board, then reconnect with Thonny.
If I run x = Pin('A11') it works fine, and then displaying x returns Pin(Pin.cpu.A11, mode=Pin.ALT, alt=10)
I can even define the pin with Pin.ALT and alt=10, but nothing else works.
This is the only pin that has this problem, all the others seem to work fine (so far...) including A10 and A12.
Is it just a faulty pin that I can never use, or is there a way to correct this? I'm suspecting the former...
All advice gratefully received.

[davefes]

Which firmware are you running? Maybe, a link to your mpconfigboard.h might help.

I have only used:
https://github.com/nspsck/STM32F411CEU6_BlackPill_Micropython

[mogplus88]

@davefes thanks for the quick reply! The short answer is I don't know for sure but it appears to be either pyboard or possibly a variation of pyboard, as I can import pyb and use the functions in it.
I had a look at the link you posted and it looks like the answer to a maiden's prayer (as my dear old mum used to say). I have tried on several occasions to build micropython for STM from source using various sets of instructions on the net, but it always fails. I will try one of the versions on the link you provided, I'm just not sure which version of blackpill I have. I have another one the same, and so far it has resisted all my attempts to load mp on it, or even work at all (tried it on Arduino ide). A complete dud maybe?...
I tried to attach a copy of mpconfig.h (renamed to mpconfig.h.txt so I could attach it), but there doesn't seem to be any indicator that it worked. I might have attached it twice...

[scruss]

when you hit Ctrl-D in the REPL, what message do you get back? (It starts with "MicroPython v1.23. …"

What chip is on your Black Pill?

Do you have the one with external flash? If so, there may be some pins permanently affected by the flash connection

[davefes]

I have built firmware using his instructions, when we were trying to sort out some USB issues. Where did you get your boards from, be aware that there are clones? Is there a chip on the back of the board?

You can do a build for the smallest flash and use that on any board ... of course NOT getting access to the added flash. I had to do that on boards with faulty added flash.

He has been very helpful in the past sorting out issues.

[davefes]

It did not attach.

[davefes]

How do you load the firmware? I use STM32CubeProgrammer-2.14.0 For file loading I use rshell and pins A9 and A10.

[mogplus88]

@davefes @scruss thanks for your replies. This is what I get with a ctrl-D:

MicroPython v1.22.0-preview.42.g2590a34ed on 2023-10-21; WeActStudio BlackPill v3.1 with STM32F411CE

I never got as far as actually attempting to flash the board as the build always failed before that. Of course I can't find the instructions I followed now, but it was the last step that failed due to missing libraries. I checked the folders where the libraries were supposed to be, and they were there, so I don't know why it couldn't find them. Anyway if there's a prebuilt version I'm more than happy to use that. I'm not techie enough to be able to sort out compile and build problems. I can follow instructions, but that's about the limit of my expertise. :(

Yes I suspect my boards are probably clones. I bought them a while back and they've been languishing in my box of bits. I don't know how mp was installed on one of them, I don't recall doing it. Maybe it came preflashed?

The chip has "stm32f411ceu6g?23211v? chn gq 224" written on it. The question marks are characters I couldn't decipher, even with a magnifying glass. There is no chip soldered to the underneath.

I have an ST-Link programmer but I have never used it. I had a couple of chips with stm chips on them but no usb plug, but never got around to actually trying to program the boards. I guess I'll be doing to reading on how to work it! I have found that, if I hit the reset button on the board, I can open it with Dolphin and see all my python files, and I can add and delete files too.

Thanks again for your help, much appreciated.

[davefes]

Which board are you building for?

[mogplus88]

@davefes it was for the Blackpill I have that wasn't working.
For the record, this is the first few lines of the error output I got when I tried to run the build (on Ultramarine and MX). I realised as I was doing this that the file objgetitemiter.c exists, that's what I checked for the first time I tried it, but I now realise it was actually complaining about the included lib stdlib.h. You'd think with all that underlining I would have noticed it, but no... I did a search for that but I couldn't find it. There were a couple of them in the micropython folder, but they were in the pico-sdk library, so not relevant to stm32 I'm assuming. I don't know where include libraries are supposed to be...

Use make V=1 or set BUILD_VERBOSE in your environment to increase build verbosity. GEN build-WEACT_F411CEU6/genhdr/qstr.i.last ../../py/objgetitemiter.c:27:10: fatal error: stdlib.h: No such file or directory 27 | #include <stdlib.h> | ^~~~~~~~~~ compilation terminated. In file included from ../../py/mpstate.h:29, from ../../py/mpstate.c:27: /usr/lib/gcc/arm-none-eabi/14.1.0/include/stdint.h:9:16: fatal error: stdint.h: No such file or directory 9 | # include_next <stdint.h> | ^~~~~~~~~~ compilation terminated. In file included from timer.c:27: /usr/lib/gcc/arm-none-eabi/14.1.0/include/stdint.h:9:16: fatal error: stdint.h: No such file or directory 9 | # include_next <stdint.h> | ^~~~~~~~~~ compilation terminated. In file included from ../../py/binary.h:30, from ../../extmod/modbluetooth.c:28: ../../py/obj.h:29:10: fatal error: assert.h: No such file or directory 29 | #include <assert.h> | ^~~~~~~~~~

[davefes]

Whose board definition are you using? In micropython/ports/stm32/boards you must be selecting a specific board. Or, whose instructions are you following?

I suspect that it was a problem with your previous build environment.

[mogplus88]

I used the one you suggested, the nspsck one.

[davefes]

OK. Now you get start making some projects.

[mogplus88]

Yeah, or rebuilding in my case. I have a couple of ancient and venerable radio control transmitters circa late 70's early 80's that I converted to 2.4GHZ with FrSky Tx modules and home brewed encoders. One using an Arduino Nano and the other using a Teensy LC. Tried them recently and neither of them worked, not sure why. The Teensy LC isn't suported any more, and the Nano was getting a bit long in the tooth, so I thought I'd replace them with something that could run micropython. I had a couple of Blackpills lying around in my parts box, so they were pressed into service. Just about got the coding done, but the hard bit is all the soldering. I also have a couple of more complex Tx's which I'm probably going to put ESP32's into, and maybe 900MHz modules, but that's a long term project...
;-)

[andrewleech]

On a related note I've pushed up a new MR for a board profile for this board: #15646
It's not reinventing anything, just taking previous definitions and bringing them up to current codebase requirements.

The schematic for the Black Pill v2.0 can be found here: https://stm32-base.org/assets/pdf/boards/original-schematic-STM32F411CEU6_WeAct_Black_Pill_V2.0.pdf

Of note, and indeed on any STM32F411, Pins A11 and A12 are the USB interface pins!
So if they're reconfigured it's expected that the USB interface would drop out, I'm surprised @mogplus88 that you could do anything with A12 without also killing the USB :-D

[davefes]

OK, got it.

You would have to look closely at the marking on the crystal on the board.

[robert-hh]

At Aliexpress they sell both the 8M and 25M version for a marginally different price. A few cent less for the 8M version.

[davefes]

Got a negative response from WeACT if they planned to make a 8MHZ 8MB variant, so I bought some 8MHz SMD crystal units. Still haven't tried swapping them out.

[robert-hh]

If the 8MHz version are only available without Flash, then it requires only a single variant.
It look as if they all will be sold next week for 99Ct including shipping!

[davefes]

https://github.com/nspsck/STM32F411CEU6_BlackPill_Micropython/tree/main/firmware has been kind enough to provide firmware for 3 variants using 8MHz for those of us brave enough to put more flash on the 8MHz boards.

Thanks for the heads-up, I would like a few more.

[mogplus88]

@andrewleech you are correct, A12 does exactly the same thing. When I was first trying to track down this problem I only got as far as
a11. But trying to redefine A12 also causes Thonny to crash. Hardly surprising if it's fouling up the usb port...
Live and learn.
;-)