Communication between Jetson TX2 and Pixhawk

I want to know is there any way to connect Jetson TX2 placed on J120 carrier board with Pixhawk
and make them communicate with each other without flashing the APSync?

If I flash APSync to the Jetson board then it is only acting as an internet
access point that streams flight data and images taken by the ZED camera. However,
in that case the GPU on board is an entire waste. I want to utilize its
on-board(decentralized) power in order to make the robot autonomous even without being
directly monitored and controlled by the ground station.

hello xuzheyuan961124,

suggest you access [Tegra X2 (Parker Series SoC) Technical Reference Manual] from Jetson Download Center.
please check [CHAPTER 8: MULTI-PURPOSE I/O PINS AND PIN MULTIPLEXING] for using I/O controls.

you may also refer to JETSON TX2 HEADER PINOUT for Jetson-TX2 J21 header pinouts.
please also check Topic 1030443 for using GPIO on Jetson-TX2.

Here you go. I created a modified version of apsync which allows you to control the TX2 directly through mavlink while having all the video streaming and telemetry functions available