This is another (and important) STM32F103 project.
It began with the fine libmaple project. This was done by Leaf Labs and is very good work.
I however did not at all like dealing with C++. The project was already partitioned with a low level "libmaple" part, which looked like original code, and was entirely in C. I have left this untouched.
The top part is what was originally called "wirish". This was almost entirely in C++. I have ported and recoded much of this to be entirely in C. I am doing more all the time and will soon have the C++ scourge eradicated. I am calling my rewrite of this section "unwired".
I took the approach in "unwired" of having a single directory with both .c and .h files. I find this far more convenient than running around in circles chasing include file paths.
I have also abandoned the multi-board support they were working on and name board specific files stm32f1-xxxx.c and such, placing them in the same directory rather than a board specific directory hidden away someplace. I am lazy and I like things simple.
This may seem cruel and brutal, but it is a hard world. It suits my purposes, and the orignal libmaple is still out there as well as STM32duino which is derived from it. I hope nobody from Leaf Labs that finds this will feel insulted.
If you are using Fedora linux and want to use USB you will need to find ModemManager and get rid of it. It will compete with you for access to /dev/ttyACM0 for the first 15 seconds and send characters to that device.
One thing I have particularly enjoyed is that I fixed an issue with the original libmaple. I use an STlink SWD dongle to load code into my STM32F103 and am used to simply typing "make burn" to load new code without having to touch jumpers. This would not work with the executables I made using the original Libmaple. This was at first confusing, and then became simply irritating. It turns out that it was the call to disableDebugPorts() that was the cause of this. This simply calls afio_cfg_debug_ports(AFIO_DEBUG_NONE). What this does is to switch the pins dedicated to SWD from being SWD (aka "debug" pins) to being plain old GPIO pins. All fine and good if you aren't using SWD and want a couple of extra GPIO pins. These are A13 and A14. On the original maple_mini these were just pins on the edge of the board, not in a handy SWD connector like on the blue pill. By default now, I do not make this call and these pins are always SWD.