practic_les2_ada_usart1_rx

-- WeAct BlackPill STM32F411CEU6 -- GPIOC Pin13 --> LED -- USART1 RX -->GPIOA Pin10 -- * If ASCII char Rx < 5, Turn On LED -- * Minicom : press 3, LED On. Press 9, LED Off -- * HSI=16 MHz,APB2ENR = 16MHz -- * Bps/Par/Bits : 115200/-/8N1 -- * Hardware Flow Control = No -- * Software Flow Control = No -- * --