PX4 with DJI Lightbridge 2 (DJI DBUS compatibility)

I was considering using a PX4 autopilot for the drone stabilization and control and the DJI lightbridge 2 for the video and data wireless transmission.

In the detailed description of the Lightbridge 2 it is shown that the RC controller commands received by the Lightbridge 2 are streamed to the autopilot through its DBUS Port.
Is the PX4 able to receive RC commands data from DJI DBUS Port of the Lightbridge 2?

Moreover it seems that it is the CAN Port of the Lightbridge 2 which is used to send telemetry data to the ground system.
Is the PX4 able to send telemetry data to DJI CAN Port of the Lightbridge 2?

Many thanks!

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I think the DSBUS is a PPM so it should be ok (I read it in another forum).
What I’m worried is about the telemetry, because I think they don’t use a transparent protocol, i.e. it is not pure MAVlink if you send MAVlink onboard. You need to go through DJY app and SDK probably, but I’m interested aswell.

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hey did you tried this?

Hi Alex,
You are able to do this. The DBUS port gives you a connector that fits as it should into the PX4/Pixhawk 2.1. The black wire (that looks like the ground wire) is the signal and the grey wire is the ground (come on, DJI). It gives a PPM signal that you will be able to see in Mission Planner when you go into the Radio Calibration. You may have to switch channels around.
I’m not sure about telemetry data. Since conventionally the telemetry data goes out through the telemetry port, it definitely won’t be a plug-and-play solution, although you may be on to something on the CAN Port. Right now, I’m using control commands through the lightbridge 2 and still using the radio for telemetry. You could see if there’s an option in the full parameter tree for sending telemetry out through the PPM r/c port but even if that works I would guess DJI doesn’t play nicely with that information in their app or HDMI display.
Hope this helps and please let me know if you are able to get things working with the telemetry as it would be helpful to me as well!

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Hi, @Yanghuang_Pu, @seaotto, @tuloski, @alexcherpi,
I would like to know how you configured DJI Light Bridge 2 with Pixhawk Cube Autopilot. Actually i am able to receive 4 RC control channels and channel 6 but i could not find remaining channels i.e. 5, 7 and 8. Can you please help/guide in this regard.

Thankyou

Regards

Yasir Khizar

There is a return home button on the DJI remote controller, that is channel 7 I remember, I can use 4 RC channels and channel 6, 7

@Yanghuang_Pu, Yes, you are right but the home button has very small change in pwm value i.e. min 1700 and max 1900… The pwm value shift is too small to be used effectively. Can you please guide whether i can use home button with big change in pwm value… Also can i have one more channel e.g. on a scroll wheel?
Thanks in advance
Regards
Yasir Khizar

Hi, I am not able to use other channels as well.
this is the DJI RC behavior, but why you say “The pwm value shift is too small to be used effectively”, PX4 can recognize the difference with no problem