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jmltt

Wanted to check in again. Any advice on swapping spektrum RC for ghost atto on voxl2?

jmltt

Hardware - VOXL2
Software version - up to SDK 1.4.0

I identified what could be a significant bug when attempting to implement offboard control via acceleration setpoints in px4 on voxl2. See this post for complete details:

ROS2 Offboard - Transitioning from Position to Acceleration Setpoints

Hello. I’m implementing a ROS2 offboard control package to fly a dev drone running PX4 (v1.14). I have it set up so that I publish offboard_control_mode messages with the position flag set true and publish trajectory_s…

Dronecode Forum | Open Source Drone Development (discuss.px4.io)

TLDR: acceleration control doesn't work because a constrain function in the MC position control code incorrectly clamps a value of NaN for vz (set in trajectory_setpoint.vz field from an external controller) to the downward velocity limit. This only occurs on VOXL2, not in px4_sitl built from the same firmware but running on my laptop.

I resolved the issue by wrapping the specific constrain function in a call to PX4_ISFINITE which just calls __builtin_isfinite(), but this raises the question of why is NaN being evaluated incorrectly within the constrain function and could checks on NaN be failing silently elsewhere in the control stack and causing other hard to track issues.

IDK if this is being caused by a compiler flag set specifically for voxl2, it's inherent to the QRB5165 hardware, or if this issue would apply to all ARM devices. Can someone take a look and provide some feedback?

jon

Hello, I am attempting to stream encoded video over a somewhat long range radio link (imx412 @ 1024x768 on the pipe hires_small_encoded).

Voxl portal:

acceptable latency & performance over ethernet
buffers and jams up when streaming over radio link

RTSP stream through vlc:

extremely high latency (1-1.5s) over ethernet
works over radio link, but with same latency issues

As far as I can tell, the encoded stream should be within 2Mbps which is well within the capability of our radios, especially at the range I've been testing, so I'm not sure why voxl-portal buffers and locks up while voxl-streamer doesn't.

Not sure if I read all of this forum page correctly, but it seems like I should not be experiencing latency nearly this bad using voxl-streamer: https://docs.modalai.com/camera-video/low-latency-video-streaming/

Let me know if I am doing anything obviously wrong. Thanks!

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ROS2 Offboard - Transitioning from Position to Acceleration Setpoints

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