Yes, we are using the Rx/Tx connectors on the Palo43. We hooked up both, not sure which I am currently using, but the other one seemed to interfere with console output, so we disconnected it. The one my signals come out from is /dev/ttyS0. The voltage levels coming out of the Palo43 are 1.8 V. We had to make a level shifter circuit to boost the signal to 3.3 V on the way to our radio, and reduce the signal to 1.8 V on the way to the Palo43. If you'd like some pointers on how to put together that circuit, I can ask our electrical engineer. BTW, since I sent the last message, I discovered that the -8 flag fixed most of the serial problems I was having, so the new agetty command is
agetty -8 19200 ttyS0
There are still some odd characters at the beginning of some lines I'd love to share findings on the serial interfacing front. Do you understand how to change a serial output from being a console to being usable for device I/O?