Connecting to QGC Via Transmitter
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Hi all,
Here is my setup:
- VOXL2 flight controller
- PX4 autopilot
- Radiomaster GX12 Transmitter
- Radiomaster RP2 receiver
What I would like to do is connect to QGC via the transmitter. However, I am unsure how to go about doing this or if it is even possible on the VOXL2. I've successfully established RC with the FC in CRSF link mode; I can see the stick inputs updating when connected to QGC via USB-C.
On other flight controllers, I have been able to establish transmitter/QGC connection by putting the transmitter in "Mavlink" mode and connecting to the transmitter WiFi. This does not seem to be working with my VOXL2. I've tried changing the /etc/modalai/voxl-px4.conf "RC" setting to "external" and "crsf_mav" and neither seems to work (maybe I'm missing something).
Any help would be greatly appreciated. Happy to provide more information as needed.
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@PatkirkMartin Mavlink over a DSP mapped UART won't work. However, if you have an accessory board with an apps processor UART available then you should be able to configure that to work with Mavlink.
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@Eric-Katzfey
Thanks for your reply! I am not attempting to establish communication via UART. I have already successfully been communicating the the FC/PX4 via WiFi, ethernet, and USB-C through the ADB shell (link). What I am talking about doing in my post is fundamentally different. I have an ELRS receiver plugged into J19 on the VOXL2. As mentioned in the above post, I have verified that the ELRS receiver/transmitter works for RC inputs over CRSF.What I am trying to get working now is using the transmitter for QGC connection. This is possible on other flight controllers by connecting to the transmitter's local WiFi or via USB, but this does not seem to be working in the same way for the VOXL2. I imagine I am missing a specific configuration option or setting somewhere, or maybe this just isn't possible since Mavlink seems to be only communicated via UDP on this device. That is what I am looking for clarity on.
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@PatkirkMartin The ELRS is connected to a DSP UART via J19, correct? That is the link that you want to send Mavlink data on?
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@Eric-Katzfey
Yes sir. I think I see now what you are suggesting. Is it fair to say that any application trying to do anything with Mavlink on this system must do so over UDP connection to the voxl-mavlink-server? I think I was operating on some incorrect base assumptions. My apologies! Greatly appreciative of your help. -
@PatkirkMartin No, as I said a UART mapped to the applications processor would also work. PX4 has a split architecture on VOXL2 with all flight critical operations happening on the DSP and support functions such as Mavlink, logging, and data manager are on the applications processor. But there is flexibility to move functions between them as needed. So, to match the ELRS receiver with the Mavlink module you could run it on the applications processor instead of the DSP. However, you would need an expansion board that exposes such a connector.
