Using Arduino on the "blue pill" STM32F103 boards
I have recently bought one of those "blue pill" development boards from the Chinese market. It's a small device that's quite capable, but more importantly, it's extremely cheap. The idea was to get started in ARM Cortex-M development with something simple.
I tried using Rust on the STM32 but for now gave up as the toolchain is just not ready. While it's possible to create a "blinking LED" demo, anything more complex will require an intimate knowledge of the STM32 which I just don't have at the moment.
So I'll be using Arduino for now. Roger Clark has ported the Arduino core to this device and a relatively big community has formed around it. The setup turns out to be quite easy.
How to get started is described on the forum but it's even easier than it might seem.
- Download the latest release from GitHub and place it in Arduino/hardware. I wanted to live on the bleeding edge so I decided to download from git instead but you should probably just download the latest stable release.
- Download the toolchain by installing board support for Arduino SAM boards (Arduino Due). Again, I was stubborn and did something else, namely modify
Arduino_STM32/STM32F1/platform.txtto to use
compiler.path, so the installer uses my system-wide ARM GCC installation instead of the one provided by Arduino.
Now, it's just a matter of opening the Blink example (File > Examples > 01.Basics > Blink) and try to compile and upload it. I first tried to just compile it to make sure the toolchain was OK. Of course, it initially tried to compile without installing the SAM board support or setting the proper
compiler.path, resulting in the following error:
fork/exec /bin/arm-none-eabi-g++: no such file or directory
Error compiling for board Generic STM32F103C series.
After fixing the compiler this issue went away.
The next problem was with uploading the program, using ST-Link (as selected in the upload method from the Arduino menu):
/home/ayke/Arduino/hardware/Arduino_STM32/tools/linux/stlink/st-flash: error while loading shared libraries: libusb-1.0.so.0: cannot open shared object file: No such file or directory
This is because the st-flash binary is a 32-bit executable and I'm running a 64-bit OS. I suspect there's an issue with the Arduino IDE: apparently it picks the 32-bit executable while there's a 64-bit one available (in tools/linux64).
$ file /home/ayke/Arduino/hardware/Arduino_STM32/tools/linux/stlink/st-flash
/home/ayke/Arduino/hardware/Arduino_STM32/tools/linux/stlink/st-flash: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), dynamically linked, interpreter /lib/ld-linux.so.2, for GNU/Linux 2.6.24, BuildID[sha1]=be1b2ce303da6d9d119783a0cc9beb59d4b9a8c0, not stripped
This is easily fixed in Debian, by installing the 32-bit version of libusb-1.0-0:
$ sudo apt-get install libusb-1.0-0:i386
Now I could upload the blinky example and see the mighty LED blink!
I have also tried to burn a bootloader on it, but I can't get it to work. If I get it to work, I'll update this post. For now, I'll just use the ST-Link.