A simple standalone library for the STM32F103C8 Blue Pill written in plain C.
You will need arm-none-eabi-gcc (I used 9.3.1) and binutils
Open an example directory in a command window and type "make", or use a code editor such as Notepad++, or an IDE like Eclipse or EmBitz. If there's a link error, you might have to manually create the Output directory.