Question regarding Crossfire/Mavlink for RC control

Ground Control Software Mission Planner
9

Ok, so, I changed serial port 1 to 23 and then in the Diversity Receiver I set “RC by MAVlink” to OFF.

This resulted in no RC but I still received telemetry. The good news is this seems to be confirmation that Serial1 is the correct setting to change.

So, the only setup that gives me everything is setting the protocol to 1 and setting “RC by MAVlink” to ON.

I have a growing feeling that I’m just missing something very simple here…

10

By the way, I’m doing pretty much what the guy is doing in this video:

11

[quote=“vronp, post:8, topic:62242”]If I change this protocol from Mavlink to RCin, do I lose telemetry as I gain RC?

I’m going to test this as soon as I figure out which SERIALn corresponds to the Radio port on the Pixhack. The port is labeled as Radio/Telem1 and I’m making the assumption this is the primary port for this data.[/quote]

AP appears to be always looking for telemetry data on SERIAL1 (and 2 as well I believe). Any OPTIONS set are merely “on top” of that. At least this seems to be the case with CRSF.

12

I left “RC by MAVlink” on as it didn’t seem to matter. Maybe that’s the setting to change?

By the way, you are using the 4.1.0 development (“latest”) version of AP?

13

If I am looking at the right thing, ArduCopter 4.0.4

I’ll try leaving “RC by MAVlink” on…

14

there’s multiple ways to combine your crossfire with your FC, as the crossfire supports various protocols. using bidirectional crsf or mavlink protocol will likely be the most attractive options. mind that crsf protocol as for now is supported in ardupilot latest (=master) firmware only.

1.: to use crsf as your RC and telemetry protocol

  • in your crossfire Rx, set the pins you use to connect to your FC to CRSF_TX and CRSF_RX
  • in MP set the serial port you use to connect your crossfire Rx to SERIALn_PROTOCOL = 23 (RCIn)
  • your crossfire’s RC by mavlink setting will have no effect in this scenario, as mavlink is not used
  • this will bring up crossfire telemetry sensors in your transmitter and, if using the fullsize crossfire transmitter, allow to pass on emulated mavlink downlink telemetry of the most vital avionics (one way only) via the TX’es serial port or bluetooth module

2.: to use mavlink as your RC and telemetry protocol

  • set your crossfire receiver’s pin functions to MAVLINK_TX and MAVLINK_RX
  • in MP, set your FC’s respective SERIALn_PROTOCOL to 2 (mavlink2 = default), and the corresponding SERIALn_BAUD to 57
  • in your crossfire RX, set RC by mavlink “ON”. mavlink2 supports the 12 channel option, while mavlink1 will allow 8 channels only
  • if using the fullsize crossfire TX, this will allow to pass on full bidirectional mavlink telemetry to your ground control software of choice (serial port or bluetooth)

mind that current crossfire firmware does not fully support mavlink bridging via wifi / udp on the crossfire microTX V2 yet.

1 Like
15

CRSF is not available in 4.0.4, you need to download 4.1.0 from “latest” folder. I already mentioned that 2 days ago but maybe not clearly enough. :wink:

16

Yes you did and I lost track of that somewhere along the way.

Well, I might have a new problem now but I’m not sure. I think this PixHack has the flash error and I can only flash 1 MB on it. I’m not positive yet and I’m still researching. Regardless, I apparently found 4.0.4 that fit so fingers crossed that 4.1.0 will fit otherwise I am ordering a new flight controller.

17

Still not working. If I don’t have “RC by MAVlink” set on the receiver, it will not work.

10/3/2020 8:37:02 AM : RCOut: PWM:1-12
10/3/2020 8:37:02 AM : Pixhawk1-1M 00290028 3034510A 30363239
10/3/2020 8:37:02 AM : ChibiOS: 331fe75d
10/3/2020 8:37:02 AM : ArduCopter V4.1.0-dev (13e5e03a)
10/3/2020 8:37:00 AM : Frame: QUAD
10/3/2020 8:37:00 AM : IMU0: fast sampling enabled 8.0kHz/1.0kHz
10/3/2020 8:37:00 AM : RCOut: PWM:1-12

18

So MAVlink is still being used, not CRSF. Are you sure you set the right serial port to 23? “Decoding CRSF” should appear among the first messages.

19

I think you are onto something. I changed each serial in turn and never saw that message. Then, I went back and disabled the Serial1 line and yet I still get RC via MAVlink. I was sure this would break RC but it did not. I’m assuming this means I am changing the wrong parameters or there is something else I am not doing correctly.

20

http://doc.cuav.net/flight-controller/pixhack/en/pixhack-v3.html

That is a picture of the FC. I have the previous version but the ports are nearly identical. I am connected to the RADIO port. I suppose I could try a connection to Serial 4/5???

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22

Unfortunately I have no experience with Pixhack/hawks, only F4/F7 FCs with UARTs. I can just say that CRSF plus telemetry only worked for me on a port dedicated for telemetry (and not the one recommended for serial receivers).

23

I guess I can try connecting to other ports and see what happens. I would think, since telemetry and RC worked on this port, albeit with MAVlink, that crossfire would also work but who knows???

24

Well, it appears the mystery may be solved. The 1M flash version of 4.1 does not include CRSF functionality.

25

I may have the identical issue, just trying to confirm. My FC is the Kakute F7 V1.5 (STM32F745) and the specs say 1Mb flash. Where did you discover that 1Mb flash does not support CRSF? Are you confident this was the ultimate reason for the CRSF rc-in failure?

26

It was revealed to me in a discussion with some developers. From what I recall, the image that fits 1 MB does not include CRSF functionality.

27

thanks, I used Yaapu’s custom build and followed instructions on that thread and I managed to get it working, appreciate the reply

28

I’m glad to hear you round a resolution. I had put this particular project to the side for a while. Thanks for the link. When I get back to this, I will give that a try.