On closer inspection the particular carrier board I was looking at actually used RS232 so an actual converter will be needed. Sparkfun has this: https://www.sparkfun.com/products/11189 which should do the trick.
Just cut the FTDI cable to whatever length you want and then solder the
pre-crimped wires onto ends of the FTDI cable wires. I think this is best
since you don’t have to get the expensive crimping tool.
The pixkawk 2.1 cable pinout is here
FTDI cable datasheet:
Connections are:
Red wire - do not connect
Yellow wire - telem 2 pin 2 (FTDI RX to pixhawk TX)
Orange wire - telem 2 pin 3 (FTDI TX to pixhawk RX)
Green wire - telem 2 pin 4 (FTDI RTS to pixhawk CTS)
Brown wire - telem 2 pin 5 (FTDI CTS to pixhawk RTS)
Black wire - telem 2 pin 6 (FTDI Gnd to pixhawk Gnd)
You only really need the tx and rx connections, but the others can be made
just cause they’re easy and no reason not to.
It shows up on the tx2 as /dev/ttyUSB0. I configure the pixkawk with a baud
of 921600 which has been pretty reliable.
When the Dev Kit is not connected to the pixhawk everything works well, only when connected to Telem2 (on the pixhawk) and the pixhawk is powered on do I get an unstable boot and constant restarts.
Second, so I understand you have connected the Dev Kit to the pixhawk via the USB exit and not the GPIO Extention Header, is that correct?
I have tried using J21 Extention header to connect to the Pixhawk:
/dev/ttyS0 is the serial console and is basically unusable for anything
else. Try reading from it at 115200. I only recently started using the
serial port directly on the Jetson. The FTDI cable was easier and faster to
get up and going.