Why use external telemetry module over onboard in FC?

[Indie_Hacker]

@Target0815

I have already flown over 50 km with all the systems mentioned. Currently I would prefer an ExpressLRS system (Radiomaster Bandit) on 868/900 MHz to all others.

Oh woow that is really impressive!! Did you use directed antenna on the ground? Which one?

[Janno (Jan Ole Noack)]

@Indie_Hacker

do you have any examples in mind?

I don’t have any personal experience with it, I just read it here on the forum.
This looks like worth a shot (Hi Reinhard ^-^):

FPV camera stream via 4G/LTE telemetry? + General questions about my ranger 2400 plane project

You can use tools such as UAV 4G Tool or UAVmatrix. They use a Raspberry PI in the aircraft (in addition to the flight controller) to communicate with a 4G/LTE stick. This can also be used to transmit (limited) video and display it in the Mission Planner.

For more examples search the forum for “LTE telemetry”

Dragonlink also supports full (two-way) MAVLink telemetry together with the RC link. ELRS currently doesn’t support MAVLink, if I’m not mistaken (please correct me if I am). Crossfire theoretically does but I didn’t have much luck with it last time I tried it.

[Target0815 (Reinhard)]

@Indie_Hacker mentioned that only normal telemetry is planned. ExpressLRS is good for that. With the branch “mavlink-rc” Mavlink will also work, but it will take some time. LTE is also a possibility.

Dragonlink is not bad, but 3.5 years no more updates and Mike doesn’t have a programmer for it anymore … the project is dead if you ask me.

I would take ExpressLRS, it is also much cheaper and can be bought at any time.

[Indie_Hacker]

@Target0815

I have already flown over 50 km with all the systems mentioned

BTW, did you get video transmitting on that range? What video setup that was?

[Target0815 (Reinhard)]

The easiest way is with analog video on 1.2/1.3 GHz. With digital video (Walksnail) I haven’t gotten over 40 km so far.

Setup tips for 1G3 video can be found here. You will soon realize that the selection has become small. I can only recommend equipment from RMRC and antennas from TrueRC.

[lida2003 (Daniel Li)]

@Indie_Hacker

@lida2003

f you are flying long range and wanna control the drone throught telemetry, then you probably need a more powerful, reliable, long range telemetry.

Yeah this is what was probably confusing me the most. Telemetry assumes data transmit to the receiver, while same time we are talking about telemetry to be a receiver for control.

And I actually plan to work on longer range flights (~50Km), so I guess I would need something more powerful. But as I figured the telemetry data isn’t that important for me as long as plane receives control instructions and I VTX work.

@lida2003

So the question is what requirement of your setup of telemetry?

The main requirement is to control my fpv fixed wing on range ~50km. Telemetry data observation isn’t as important to that moment.

That’s good. At least we have a very clear requirement: ~50km long range flight, mainly focused on RC/Video link.

When Video link is broken, it’s hard to recover, especially long range, even if analog VTX when turn a round the antenna is blocked (partially blocked) by battery or companion computer etc.

When video link is down, it’s impossible for FPV pilot to operate the drone. Then if telemetry is OK, we can still navigate the drone(RTL or smartRTL is NOT that smart actually, maybe some expert with carefully setup for rally points might to the smart thing) from MP or QGC and know where it is. If crash, we can know where it crashed ( last know position will be send out by telemetry.

That’s the advantange of dual link control. And of course, low power telemetry or PCB antenna??? is useless for such long range flight.

– EDIT

BTW, mostly VTX works on 5.8G/2.4G/1.2G etc, and RC link works on 2.4G/915M/868M etc. Some known telemetry module works on 433M/868M. In the same situation, low frequency is much more likely to transimit far away.

Maybe switched to 4G LTE module is a good choice for civilian usage: vdeo and telemetry( for long range) Ah~~~~ that’s the DJI drone.

DJI remote controller
DJI goggles
DJI airunit
DJI mobile app (video + telemetry, app guided fly)

[Indie_Hacker]

@lida2003

When video link is down, it’s impossible for FPV pilot to operate the drone. Then if telemetry is OK, we can still navigate the drone(RTL or smartRTL is NOT that smart actually, maybe some expert with carefully setup for rally points might to the smart thing) from MP or QGC and know where it is. If crash, we can know where it crashed ( last know position will be send out by telemetry.

Very good points. I will dive deeper to learn more about MP and QGC stuff, and probably re-consider my requirements regarding telemetry.

@lida2003

Maybe switched to 4G LTE module is a good choice for civilian usage: vdeo and telemetry( for long range) Ah~~~~ that’s the DJI drone.

First I thought I could do LTE. But now I figured is probably not an option for me due to bad coverage in the area of flights, most likely there is no mobile signal at all

[lida2003 (Daniel Li)]

@Indie_Hacker

@lida2003

Maybe switched to 4G LTE module is a good choice for civilian usage: vdeo and telemetry( for long range) Ah~~~~ that’s the DJI drone.

First I thought I could do LTE. But now I figured is probably not an option for me due to bad coverage in the area of flights, most likely there is no mobile signal at all

Then you can checkout this Global Satellite Telemetry for ArduPilot , or sort of this kind of comm link for telemetry.

Well, it all depens on the requirement. I think it might cost much

— EDIT

BTW, here is a list for ardupilot Telemetry (landing page) — Copter documentation