practic_les1_ada_usart1

-- WeAct BlackPill STM32F411CEU6 -- GPIOC Pin13 --> LED -- -- USART1 TX -->GPIOA Pin9, RX -->GPIOA Pin10 -- * HSI=16 MHz,APB2ENR = 16MHz -- * Baud rate = 115200 -- * Stop bit=1 -- * no flow control -- * data =8 bit -- *