[fake-stm32-blue-pill-board] STM32F103C8T6 Bootloader/Sketch problems

[BennehBoy]

Once I enable CDC and use Serial.begin compilation fails with an out of ram error (need another 1K). If I compile for a standard blue pill with 64 or 128K, compilation is successful.

AH OK gotcha, yes, the current github base version of CDC has ~ 6K of buffers allocated, there's a PR in that shrinks this down to ~256 bytes, see PR#399 -> https://github.com/stm32duino/Arduino_C ... 2/pull/399

It's awaiting a rebase, which I guess Frederic will get around to this week.

[fpiSTM]

Right. I will try to do it this week but I will not be available a part of this week for personal reason. My father-in-law is dead and I have to take care of my children this week.

[BennehBoy]

Sorry to hear that Frederic

[fredbox]

Which things?

I've had a few days to experiment with the "official" core. on my fake and genuine blue pill boards. I guess the main thing I miss is an easy to use hardware timer. I compiled the blink example using a timer from another thread and it works, but is a bit more complicated to set up. Also timer related, I use systick_attach_interrupt() in Roger's core for blinking leds and scanning inputs such as rotary encoders and switches. I'm sure it will get easier as I read the documentation and get more familiar with the core. It took a while to get comfortable using the Roger/Leaflab core.

[RogerClark]

Did you manage to read the chip ID to identify which STM32Fxxx it is ?

[fredbox]

st-info, ST Demonstrator GUI, and STLink-Utility all identify it as chip id 0x412, 32K flash, 10K ram.
The part number from the STM datasheet for a part with these specifications is STM32F103C6T6. I copied the linker script and added four lines to boards.txt for the fpiSTM core with for a part with these specifications and it appears on the menu as a blue pill with 32K. I can compile and upload simple programs and they execute successfully. Serial works on the UART pins, but USB serial takes too much memory for now.

[mrburnette]

...
Serial works on the UART pins, but USB serial takes too much memory for now.

USB serial is vastly overrated

While using a Maple Mini clone with USB serial is "nice" for debugging statements on the ArduinoIDE serial console, it rarely is needed after development where a Blue Pill or this new resource crippled-Bluepill will suffice.

With the increased Internet stories about the under $2 Blue Pill, the demand was sure to create a market for Asian suppliers of fake merchandise. I strongly suggest all who are in receipt of fake marketed Blue Pills to demand a full refund... only then will distributors vet their suppliers to ensure quality parts. But, if the seller refunds your money and allows you to keep the faux board, it still has project value.


Ray

[BennehBoy]

It may be overrated but it's very handy for bootloading. (although with 32kb flash I concede the point on this chip... still 2kb hid BL)

[RogerClark]

I've also used Serial USB in some of my projects, hence the current screw up when I removed the requirement for devices to set DTR, as a lot of software (in my case it was Stellarium) does not set DTR

[mrburnette]

I've also used Serial USB in some of my projects, hence the current screw up when I removed the requirement for devices to set DTR, as a lot of software (in my case it was Stellarium) does not set DTR

It may be overrated but it's very handy for bootloading. (although with 32kb flash I concede the point on this chip... still 2kb hid BL)

A few years back, I purchased a large number of those Chinese CH340'ish adapters. I find this to be a preferable solution and removing USB-serial from the Pill board leaves the uC without the need to deal with CDC serial concerns - just makes a software design a wee bit simpler with interfacing requirements can be moved to dedicated hardware. I just checked AliExpress, the CH340 is only $0.59 quantity one, free shipped.

Ray