VAR-SOM-AM43 RS232-Port
From Variscite Wiki
VAR-SOM-AM43 - RS-232 port
Start minicom. Then type characters to screen.
minicom -D/dev/ttyO2 -b115200 -8
You can use a loopback (short pins 2 & 3 in J8 on DVK) or connect to anther computer.