Wifi backpack & radio communications.

I am after some help, I have built a survey USV.

Setup: Matek h743 slim FC, Matek M10q-8553 gps module, RM RP4TD receiver, RM tx15 transmitter.

Fc is signalling pwms to 12v dc motor drivers, which in turn are powering 12v dc brushed motor, 1x propulsion motor, 1x steering box, 1x linear actuator for a deployment mechanism and 1x steering both for angle adjustment on mechanism.

Issues:

  1. I was trying to setup wifi back pack for remote telemetry observation and after i had tried my radio lost communication with the receiver and couldnt get it back no matter what, so now i have a new FC & Receiver.

I now have communication and can control all my servos again although i still cannot get wifi backpack to work and i can see my servos moving when in servo outputs page but i can only see one radio output (ch 3 or ground steering) on my radio calibration page. Could i be stuck in a wifi mode on my transmitter or something similar.

I did not replace my gps module but now i cannot get my module to correctly display yaw, pitch and roll. Even after succesful calibrations. this is stopping me from arming as i am seeing uneven mag cals and interference levels although the setup was the same as prior.

All was working correctly before this happened and i was water testing to fine tune the autopilot as it was very aggressive. took it off to set some parameters and wifi backpack and then it wouldn’t connect.

Also when wiring in both FC, the Uart that is suggested to wire the receiver into (UART 6) it not see any radio signals in radio calibration, it is only when i wire it into UART 4 that i see it on radio calibration.

The basics are done all my parameters are in spec and wiring is good, I am having some very weird and wonderful things happening and i was wondering if anyone knows of any common radio to receiver issues on the Mateks or ardupilot.

TIA

Hi @sebbirkner,

I’m not sure what the “wifi backpack” refers to so I’m not sure I can be of much help. A random guess is that a SERIALx_PROTOCOL or SERIALx_BAUD parameter has been set incorrectly but no log has been provided so it’s all guesswork really.

ArduPilot supports many telemetry systems which are here on the wiki.

Wifi backpack is the wifi the transmitter emits so that a laptop can connect to unit to show telemetry instead of a cable. It uses the radio to transmit the telemetry so you can remotely monitor.

My baud and protocol parameters are set correctly. When changed to different values it also doesn’t help.

I believe you are talking about ELRS.
You need a transmitter and receiver that can do Mavlink, and not all receivers can do that.
I have not done this myself at this stage so cant help much more, but maybe some ELRS people can chime in.

Is this what you’re looking for?

It works best on ELRS 4.0 and using hardware with the LR1121 chip (I use the RM Nomad module and XR4 receivers.)

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I am using a RP4TD RM receiver for my crsf protocol to control my flight controller, can i use the same receiver to do MAVlink, i have tried changing all protocols and settings as instructed to mavlink, ie link mode in lua script, reciver protocol, rc protocol on ardupilot and RSSI type 5, with no luck.

I loose radio control with the vessel when doing so as i beleive its changed the protocol an cannot use MAVlink to control the vessel over radio or am i wrong?

Thanks for you help

Yes, you can use that Rx for mavlink.

If you are using ELRS 4.0 there is an error in the ELRS wiki instructions. With the radio and receiver connected you can use the lua script to change to Mavlink. As long as both radio and receiver are connected you change to Mavlink on the radio settings and it will change the RX over automatically.

I am using 3.6 as I was told the 4 might brick the transmitter.

I can switch the mavlink fine, chage the receiver protocol over wifi network page. although I now know you can do it in lua script.

And change the serial port that has my receiver wired in on ardupilot to mavlink 2.

I then loose my communication to the fc and still won’t get the connection to mission planner.

At this point I have tried multiple times and I think I will get a sik radio if I can’t get it to work.