UART

Tx -> Hello World

Echo -> Rx -> Data -> Tx

https://gist.github.com/tzechienchu/35f4bfd044035b43ada9f9162ad21ef7

https://gist.github.com/tzechienchu/7d16f341b049f4ea66f1cbc58524ffc3

Since I don't have the UART ->USB converter. I can only rely on use simulation.

PS. I forget I got wio terminal. I should give it a try.