Nice trick to debug STM32 (and most cortex M cores): improved assert
Something wrong with asserts is that you dont really know what to do with them. Print something, store stuff somewhere, put a breakpoint on it The problem with embedded debuggers is that the number of hardware breakpoints is small (~4 or so), so putting one there will consume one of those precious few. Or you could add __asm__ ("bkpt 1"); To your assert function. That will stop the debugger without consuming a breakpoint.