So, I've got a development board Digi ConnectCore Wi-9C (digi.com/products/model.jsp?mid=576). There is need to establish connection between Digi and another board by UART.
At the beginning I wrote a code for serial communication between PC (running Kubuntu, there was program) and laptop. It was Ok, all worked.
Next step was to establish connection between Digi and my laptop. I compiled the same code for Digi board (dev/ttyS0) and experienced a problem: I can send data, but can't receive any byte!
I've tried blocking and non-blocking regimes, but nothing helped. No data was received.
By the way, Linux console (on Digi) is working properly (dev/ttyS1).