Anyone doing FPV on their Rigs?

[kazetsukai]

What is your longest range, using your system?

So, lets put a big asterisk on this reply first... your mileage will vary, literally.

With this HM30 system, my longest distance (GPS, straight line) is 650ft. **

*1- The test area (relative to the location of the ground station) is surrounded by unfavorable elevation change. This is the largest distance I can get the TRX-6 away before the vehicle is eclipsed by the ground, at which point no digital video system in these bands can save you, at least not that I'm aware of. There is quite a bit of foliage in the way at the point too.

*2- Stock/omnis, no other antennas have been tested on this location.

*3 - Terrain- there is a field that goes downhill from this property and opens up the distance quite a bit I could travel without eclipsing the vehicle but it is poorly mowed. The TRX-6 is too small to navigate these fields, so I have a 1/6th scale vehicle on order to try and challenge this path.

With the UniRC system, my maximum has been 2500ft (GPS, straight line). The vehicle traveled closer to 2.5 miles to get to this distance in the test, this is at a local park and elevation is close to ideal, I ran from one edge of the park to the other and couldn't get the vehicle further away to test (bordered by a river and a roadway). I can / probably should test the HM30 here, I imagine the same results more or less. There is one part of the park where elevation eclipses the vehicle and you do see signal/video feed degrade in that spot quickly.

There is another open field visible from the same park across the highway, I have wanted to also test a second person running the car over there, which would put me a little over a mile away if it were to work. My guess is it would, but if you lost signal, regaining the link could be difficult. Directional antenna would greatly help here.

I read a bit into the mini crossbow documentation, and I've seen people run the HM30 on it- you would need a flight controller / GPS vehicle side. I still don't quite understand how the tracker determines direction from vehicle position (it would seemingly also need its yaw + its own position, maybe it has internal GPS?). But I do want to get this working soon.

Hope that answers your question.

 

[Grandad]

Awesome reply, thank you for taking the time to explain.

For my setup, I have only used it around town. LOS, I can get 600 meters on the stock receiver.
Using a TBS Crossfire, along with Vas Crosshair Extreme, VAS Pepperbox and an Omni I am able to drive around the block, as well as other parts of town. Like down the raod 200m and then turn into another street and travel 200m ect.

I have a brilliant location for a LOS test, but have not tried it as yet. It is a road to another town, which is straight for 50k's and has a large hill that overlooks the road at the beginning. I plan to use this raod to test the various antennas I have, to see which is the best setup. I will also be able to test Penatration as well, by Turning off the road onto dirt roads that are situated a various distances.

The MDF Mini Crossbow would be awesome to use, ecspecially here around town, I will be able to mount it on a 6m mast. Unfortunately, there is not a lot of info for it. Not that I could find anyway. At my age, the ole brain doesn't work as well when trying to figure this stuff out.
I did purchase the MDF TelyTiny Fly, and I assume this simply goes in the car and is wired up. It then sends the signal to to Mini Crossbow so it knows where it is in the world. But I am assuming this is for Analog only and not Digital systems.

 

[kazetsukai]

So, a few things going on today since my reply- one, I did order a few things from SIYI, mostly cabling, but also one of their ethernet hubs and an HDMI output device that can link to the HM30 as well as overlay OSD information on the video.

I also tested some directionals SIYI ships with their equipment:

I had some better luck at the 650' point but also later discovered I was about 60 degrees off target. For this specific problem though I think my original point on more elevation being more helpful probably stands. There are telescoping 20' tripods on Amazon, I think I may try one in this location.

On the MFD crossbow system, it appears that many analog use cases involve an OSD chip of sorts encoding the GPS data into the video stream. This is fairly complicated. For digital however, things can be much simpler- the simplest seem to be MAVLink capable flight controller and UART. ArxangelRC did a series of videos showing this:

You can see he briefly shows the setup with the HM30 mounted directly to the MFD:

From the side, you can see the HM30's UART port taken:

I do have another HM30 compatible setup which runs our RC lawn mower and has the flight controller, although I use the MK32 for the ground station on that one (essentially the HM30 bolted to an Android tablet controller):

The "control box" I built has the HM30 air unit, but also SIYI's N7 flight controller, which is a PX4 compatible unit running ArduRover.

There's some other things going on in that box, but I highlighted the important pieces. Basically, if you have a Mavlink capable controller with GPS and UART back to the MFD, it is pretty close to plug and play.

I have a second body for my XRT so that it can moonlight as a test platform for the UniRC 7, it has essentially the same setup, sans the mower funkiness. Here you can see the GPS puck on the rear in addition to the camera top and center:

Which goes into the same flight controller underneath, as well as SIYI's UniRC Air Unit.

I might actually have the MFD figured out tomorrow. Let me know what your serial link looks like, we might be able to make it work.

 

[Grandad]

You are far more advanced and knowledgeable than myself. I might have to save some pennies and invest in the Siyi gear.

At present, I think the only way to get the signal to work is through the TBS Crossfire. It uses CRSF and also Mavlink. But this is getting beyond my knowledge, but I enjoy this? So I am happy to learn

 

[Grandad]

I also have a Matek flight controller and Matek GPS unit, but again, I don't understand how to connect them to an rc car, or use the software Ike INav etc.

 

[kazetsukai]

@Grandad I did some digging this weekend on the MFD tracker and will be testing it this week, I'll let you know my findings.
I saw a video of someone with an ETHOS/FrSky controller sending GPS telemetry over bluetooth, that is for me at least the most convenient option so I will be trying that first.
After I will try to get it working over the SIYI datalink (Mavlink or serial), and when I have some success will be writing up a HOWTO.

 

[Grandad]

That's sounds great. I have the tellefly tiny and plan on trying that next week. So I will also let you know how that goes.
Having the AAT will make so much differance.