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, send to USART1 data read from other, you can send "2\n" or "3\n" to USART1 for tests of USART2/USART3