Hello. I’m using stm32f407VG discovery and Keil uvision 5 and I can’t find an indtruction how to set clock properly. I wanna use internal 16 MHz SYSCLK for communication throughout virtual COM port. Here is a code I have found in a book, but it doesn’t work. I think the problem is a clock. I have set PLL_M in system_stm32f4xx.c to 16, HSE_VALUE in stm32f4xx.h to 8000000, but it still doesn’t work.
Just don't start the PLL, by default the chip will start and run from the 16 MHz HSI