------------------------------------------------------------------------------ README ------------------------------------------------------------------------------ This example program echoes data sent in on USART2 on the ST STM32F4DISCOVERY eval board. Uses interrupts for that purpose. The sending is done in a nonblocking way. Board connections: ------------------ PA2 (USART2_TX) TTL serial output (38400,8,N,1) PA3 (USART2_RX) TTL serial input (38400,8,N,1)