Samples for STM32F303

Most of these samples works with my non-solder devboard

blink - simple LEDs blink on PB0 and PB1
usart1 - read data from USART1 and send it back (blocking sending)
usarts - work with all three USARTs with Tx DMA, send to USART1 data read from other, you can send "2\n" or "3\n" to USART1 for tests of USART2/USART3
floatPrintf - work with floats, convert floating point number into a string
usart1fullDMA - USART1 Rx and Tx DMA access (Rx terminated by character match of '\n' or buffer overflow).