CE / FCC

[Mark The Droner]

RTH is easy to send regardless of setup and/or connection. All you have to do is turn the controller off.

... DJI Susan just confirmed what I mentioned before. No confusion there any more.

DJI Susan's post contradicts your information. According to you, when the freq is 2.4 between the AC and controller, the freq is 5.8 between the controller and mobile device. But that doesn't make sense because if that was true, people in the USA who are using 2.4 between the AC and controller would likely not have connection with the 5.8 between controller and mobile device. I believe the connection between controller and mobile device is 2.4 in the USA, regardless of what it is between AC and controller. I may be wrong, but that is what seems to be implied and that is what she seems to be saying in her post.

For safe flight first you need is reliable control signal, than telemetry and at last video feed. Not to mention that video signal occupies most of the carrier signal (for commands and telemetry you basically need few bytes of info). Philosophy is very simple, you must be able to send command "RTH" even without video and telemetry feed, regardless DJI Go setup. At least I would do it that way...
....

It's easy to send an RTH command to AC at any time regardless of what is happening. Simply turn off the controller. This initiates RTH every time.

Wait.

Turn on the controller.

Wait. Ignore the app.

When you see the AC in the sky coming towards you, you can then cancel RTH and land the AC.

 

[VonMacher]

DJI Susan's post contradicts your information. According to you, when the freq is 2.4 between the AC and controller, the freq is 5.8 between the controller and mobile device. But that doesn't make sense because if that was true, people in the USA who are using 2.4 between the AC and controller would likely not have connection with the 5.8 between controller and mobile device. I believe the connection between controller and mobile device is 2.4 in the USA, regardless of what it is between AC and controller. I may be wrong, but that is what seems to be implied and that is what she seems to be saying in her post.

Why wouldn't they? Off course it is mobile device capabilities dependable - is it dual band WiFi or not? It works for me one way or another, must work for them as well.

It's easy to send an RTH command to AC at any time regardless of what is happening. Simply turn off the controller. This initiates RTH every time.

Off course it is doable that way, but I would consider it as "extreme measure in desperate situation" for a lot of less experienced pilots. To turn off RC, lost communication with mobile phone, try to reestablish it again while bird is who knows where, maybe app will crash... A lot of things could go wrong leading to unpleasant situations.
It is easy for you, but for lot of people is a mess I believe.

 

[Mark The Droner]

What I'm saying is, I think many people in the USA are not expecting to get a wifi signal in the 5 ghz band, and their mobile device may not be capable of receiving 5 ghz, or it may not be set up to receive 5 ghz. And so we would see a lot of posts from people complaining about this right out of the box - that is, if their AC / controller / mobile device is behaving the way you say yours is behaving.

Re the RTH, what do you propose to make it better?

 

[VonMacher]

Re the RTH, what do you propose to make it better?

Nothing. DJI made it perfectly.

 

[zaulino]

Hello,
I'm french and i have the same problem as Virtual 27. I confirm that it is specified 500 meters distance in datatsheet for CE mode. I am really surprised to read "I can go up to around 3km" with "CE mode"... I think you are in fcc mode because the mode is automatically switched with GPS position (it is specified 2000 meters distance in datatsheet for FCC mode) . I confirm that Magic Power works only for Ph Std and 4K . I look for another solution
Sorry for my bad english
Guilhem

Hi, you've found a solution.
if you please share it

 

[VonMacher]

Just as information...
Today I've been testing both frequency bands (5.8 - default and 2.4 - optional), with mobile device Samsung Galaxy S8 at the very same spot I fly all the time.
Note: this is test within a CE region.
Results:
- RC to drone band 5.8 gHz, RC to phone 2.4 gHz.
Slightly better performance compared to my Meizu MX5 mobile phone. Picture more fluid, range slightly improved (maybe up to 100 meters more, 300 i total).
- RC to drone 2.4 gHz, RC to phone 5.8 gHz.
A way better performance with great FPV feed up to 300 meters. Didn't go further but that was enough for me to find this frequency combination a way much better.

Now waiting for my ARGtek kit to do some more tests, and off course for CE to FCC solution.

 

[PhantomFlyer3SE]

Just as information...
Today I've been testing both frequency bands (5.8 - default and 2.4 - optional), with mobile device Samsung Galaxy S8 at the very same spot I fly all the time.
Note: this is test within a CE region.
Results:
- RC to drone band 5.8 gHz, RC to phone 2.4 gHz.
Slightly better performance compared to my Meizu MX5 mobile phone. Picture more fluid, range slightly improved (maybe up to 100 meters more, 300 i total).
- RC to drone 2.4 gHz, RC to phone 5.8 gHz.
A way better performance with great FPV feed up to 300 meters. Didn't go further but that was enough for me to find this frequency combination a way much better.

Now waiting for my ARGtek kit to do some more tests, and off course for CE to FCC solution.

In your understanding do you chose in dji go app the RC to drone frequency, and the phone to RC frequency will be automaticly in different range? I understand you right?

 

[VonMacher]

In you understanding do you chose in dji go app the RC to drone frequency, and the phone to RC frequency will be automaticly in different range? I understand you right?

Yes, this is correct. It will change automatically. What you have to do is go to your phone WiFi settings and reconnect WiFi to your RC. Only thing necessary - your phone has to have dual band WiFi.

 

[PhantomFlyer3SE]

Now waiting for my ARGtek kit to do some more tests, and off course for CE to FCC solution.

Please share with us the outcome with ARGtek, if you can.

 

[zaulino]

I've seen some battery-powered amplifiers around.
For example:

Has anyone tested them with the PHANTOM 3 SE? Results?
I'm an italian frustrated by the ce which limits me to about 500mt

 

[Mark The Droner]

...
I'm an italian frustrated by the ce which limits me to about 500mt

 

[zaulino]

I have no idea how to do 4 km, I can not do more than 400 mt

 

[VonMacher]

I've seen some battery-powered amplifiers around.
For example:

Has anyone tested them with the PHANTOM 3 SE? Results?
I'm an italian frustrated by the ce which limits me to about 500mt

Well, there is nothing to test really.
If you boost your transmitting signal just on one side (in this case RC side), the drone will receive a much stronger control signal, but nothing is about to change regarding video reception, since drone transmitting signal stays the same (20 dBm - 100 mW). Real deal would be to install boosters on both sides, but drone will suffer from extra weight and energy consumption.

The other thing we can do is to install better antennas on both side. Again, not a big problem on RC, but drone is always a bit tricky.
I have installed ARGtek dual band antenna system. Still testing it, not a big improvement so far.

My solution is to wait for FCC hack. That will boost both sides transmission to 27 dBm - 500 mW, and that is the cleanest way.

That video Mark the Droner posted, I just can't believe it is possible with stock system in CE environment, regardless almost ideal conditions.

 

[zaulino]

ok, I agree, but the solution of the ack seems long, DJI has not released and does not seem to have an SDK for P3SE ...

 

[Mark The Droner]

We theorize that the SE uses Lightbridge, and the more time that goes by and the more evidence that is gathered, the stronger the case seems to be for a lightbridge connection, even if it's a dumbed down version relative to the Advanced and Pro.

I would love to see the controller opened up so that we can follow the antenna leads. If there are only two antenna leads - one to each antenna - that would further strengthen the case for Lightbridge.

But this controller only has one visible antenna seen from the outside. We know it must have a second antenna - or at least a second antenna lead. Does it have a patch antenna hidden inside the controller like the Standard? Or, is it possible there are two antenna leads going up one antenna mast, like the P3 4K?

VonMacher, you say you have already modded the controller, so you must know what it looks like inside...

 

[PhantomFlyer3SE]

We theorize that the SE uses Lightbridge, and the more time that goes by and the more evidence that is gathered, the stronger the case seems to be for a lightbridge connection, even if it's a dumbed down version relative to the Advanced and Pro.

I would love to see the controller opened up so that we can follow the antenna leads. If there are only two antenna leads - one to each antenna - that would further strengthen the case for Lightbridge.

But this controller only has one visible antenna seen from the outside. We know it must have a second antenna - or at least a second antenna lead. Does it have a patch antenna hidden inside the controller like the Standard? Or, is it possible there are two antenna leads going up one antenna mast, like the P3 4K?

VonMacher, you say you have already modded the controller, so you must know what it looks like inside...

You can see the inside of SE controller in that video:

I wonder that you think that SE would use Lightbrige. It seems to me, that the clear communication of DJI is that Standard, 4K and SE are wifi drones. And wifi is standardized communication. But as far I heard Lightbridge is not a standard, it is a special own developed technology of DJI which use the band range of WIFI devices - because that range is allowed for public usage.

 

[Mark The Droner]

Okay, thanks.

Re the lightbridge theory, see this thread: lightbridge on SE?

This video above shows three antenna leads. The three leads look like standard wifi controller connections - one for control and two for wifi which switch.

Does this kill the lightbridge theory?

We already knew the controller had wifi because the connection from RC to mobile device is wifi. So we shouldn't be surprised to see wifi.

But still we see only one other antenna lead which is not what I'd expect on a lightbridge controller.

Could it be the one antenna lead is coming from a lightbridge transceiver and is a two way antenna?

 

[VonMacher]

Okay, thanks.

Re the lightbridge theory, see this thread: lightbridge on SE?

This video above shows three antenna leads. The three leads look like standard wifi controller connections - one for control and two for wifi which switch.

Does this kill the lightbridge theory?

We already knew the controller had wifi because the connection from RC to mobile device is wifi. So we shouldn't be surprised to see wifi.

But still we see only one other antenna lead which is not what I'd expect on a lightbridge controller.

Could it be the one antenna lead is coming from a lightbridge transceiver and is a two way antenna?

I did some deeper digging into the system.

1. Link to drone, both frequency bands, is established by two flat antennas inside the RC. If you look at the RC back side, it is that lower (bigger) Tx/Rx box, where both RF cables for antennas come from. So this link uses both of those antennas. If I remove one (doesn't matter which one), signal strength will drop but you can still have both video and control.
2. Small Tx/Rx box (upper one), where that outer stick antenna is connected, is just for WiFi communication RC - phone device and nothing else. Believe me, I was very surprised by that fact, but that's the way it is. Basically I can fly without that antenna (tested that), just WiFi signal to phone will drop (checked with WiFi analyzer). So this small stick antenna has nothing to do with RC - Drone communication, no matter what frequency band I use. WARNING! This stands just for P3 SE system. Probably it is not the case on P3 Standard or 4K, don't know that. Can test what I have...

I believe Lightbridge is well improved WiFi standard comm, where special set of instructions and protocols do the job much better compared to P3 Standard or even P3 SE.
P3 SE is somewhere in the middle of all of that. The most obvious difference I can see is OTG cable, where P3 SE doesn't have this capability.
How to know whether this in Lightbridge or not, I honestly don't know, except obvious testing results comparison we experienced from both systems, over and over again.

What is obvious, 100 mW (20 dBm) is a way to weak transmission signal to have fluid FPV experience even within close range (up to 300 meters), no matter how good antennas I have installed on my RC. I have to boost signals on both sides (either FCC norm or boosters), but this is other story.

 

[Mark The Droner]

Good work, VonMacher.

That sticker on the smaller transmitter looked vaguely familiar. It starts out ... MAC 60601F... and so I did a quick search and found those numbers coincide with the old MAC addresses we used to need to bind a new camera to the 2.4 transmitter and flight app and make it work on the Phantom 2 Visions.

Here is a random thread I found in a quick search:

Tutorial: How to get the MAC address of a new camera

https://phantompilots.com/attachments/p2v-ch-11-png.7471/

On the Vision though, the MAC address was associated with the transmitter in the camera on the AC (If you bought a new or used camera, it would include a MAC address which you would type into your app during the binding process). In this case, it seems to be associated with the transmitter in the controller. So this makes sense if the MAC address is needed to handshake between one end of the wifi connection and the other end. In other words, this seems to strengthen the lightbridge theory because it appears the wifi starts and ends with the controller and flight app. Furthermore, the two patch antennas must be the two lightbridge antennas in the classic lightbridge systems - one for receiving and one for transmitting.

This also explains why DJI uses two different colored cables (one grey, one black) coming from the lower transmitter.

 

[Mark The Droner]

Re the FCC/CE mode of those flying in Europe, I have messaged Marco Fan who flew his SE 4250 meters in Italy. He says he did no mods at all. Everything is stock. BUT - - he has the DJI Go 4 app installed on his mobile device which he uses to fly his Mavic and that app is "modded" (I read it as "hacked") to work as FCC mode in Europe - SO, he wonders if there isn't some kind of intersection between the two apps that causes the straight Go app to use FCC mode - and I do too!.