Realsense and UP^2

Following the instructions here (Intel RealSense Depth Camera — Copter documentation), I was able to get a Realsense D435 camera to work with the Pixhawk via an Intel Up Squared companion computer running APSync. It works great, and I get readings that correspond to the distance of different objects from the sensor via Mission Planner.

I have a second Pixhawk that I can duplicate that behavior with using the same hardware. I got a second Up Squared computer, followed the same instructions, but cannot establish a connection between the Pixhawk and the new Up Squared unit. Using the command line interface and running the start_d4xx.sh script, I’ve confirmed that the new Up Squared is connected to the D435 camera and is attempting to send information to the Pixhawk. By taking the Pixhawk and connecting it to the Up Squared/D435 on the working aircraft, I have also confirmed that the Pixhawk is operating correctly and can utilize the serial data produced by APSync. I’ve checked my wiring, plugs, and pinout, and everything appears to be fine…but, for whatever reason, the new Up Squared will not establish communications with the Pixhawk.

I know that I don’t have much by way of debug data here, but I’m also not sure what is helpful. It can be produced on request, however. Any help is appreciated.