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Tello WIFI channel selection

Yes, it does work. However it would be preferable for the repeater and the Tello to operate on different channels to minimize interference. Unfortunately, I can’t see a way to do that using the Xiaomi 2 repeater.
 
Hi,

For your information ;)...

Some weeks ago I bought an ESP8266 WIFI chip ESP8266 - Wikipedia

I can confirm it's a very interesting low-cost investment.

In my case, I am trying to use it to get Tello choosing WIFI channel that I want.

My plan is writing a little script for flooding neighbour WIFI channels with fake data, letting free only the channel I want Tello use for comunications. Once Tello make its channel decission I'll switch off ESP8266 for no WIFI disturbance.

That's my idea. I´ll keep you informed

All the best.
 
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I just had an idea.
Parrot Bebop has a "wifi country" selector where you set the country you are in. This affects the available & preferred channels and Wifi trx power to stay within legal limits.
There is a significant difference in trx power between US and DE for the Bebop (I read around 7x the power but never bothered to check).

Tello has e region setting, too. I don't know what its used for, but I read out mine and it's correctly set to "DE". So it has been set, I guess during initial setup with the stock app. I doubt that Tello has to crop the trx power to be legal, but at least the wifi channel selection could be affected.

I have yet to check which command set the region.
 
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I just had an idea.
Parrot Bebop has a "wifi country" selector where you set the country you are in. This affects the available & preferred channels and Wifi trx power to stay within legal limits.
There is a significant difference in trx power between US and DE for the Bebop (I read around 7x the power but never bothered to check).

Tello has e region setting, too. I don't know what its used for, but I read out mine and it's correctly set to "DE". So it has been set, I guess during initial setup with the stock app. I doubt that Tello has to crop the trx power to be legal, but at least the wifi channel selection could be affected.

I have yet to check which command set the region.

GREAT idea @volate!lo playing with region setting.

As you know, allowable WIFI channels changes depending on the country. USA wifi channels go from one to eleven, rest of the world includes channel 12 and 13 and Japan can use special channel 14. As more exotic the channel used by Tello, better the transmission will be ;)

Problem is I have no idea about how to change region setting. Can you give us any clue ?

Thanks a lot.

raul
 
I suppose it is somehow set when you connect to the drone for the first time. The Ryze Tello App will just pick the region you are currently in.

If I find the time I can look into the data exchange during installation.
 
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Hi,

I got it ! ;)

I have achieved Tello starting in desired WIFI channel or nearby. Let me explain my method:

First, you need to take a look this hacking project spacehuhn/esp8266_deauther As you can read, its based into esp8266 WIFI chip and focused on "Scan for WiFi devices, block selected connections, create dozens of networks and confuse WiFi scanners". We don't want bothering anyone, just create some fake networks and forcing tello to choose a free WIFI channel.

I bought one of recomended pre-build Deauther board at Maltronics web store. I choose the simplest and cheapest, It seems a common USB stick: WiFi Deauther USB

wifi deauther maltronics usb stick.jpg

As soon as you feed Deauther Stick using a powerbank it starts working autonomously, but if you plan to program it you will need plugging it into a computer/smartphone USB port and opening a serial communication window. Here a typical session:

deauther serial session.jpg

Typing command "add ssids x -cl 9" you prepare 9 fake wifi networks called "x" at channels one to nine

After that, typing "attack beacon" fake networks creation starts.

At the end, "stop all" quits.

For simplicity I wrote a simple auto-executable script autostart.txt that automatically starts as soon as you plug Deauther Stick into a powerbank:

Code:
stopap
set beaconChannel true
attack beacon

And here you can see how it works. Notice fake "x" WIFI networks at one to nine channel:

deauther fake wifi.jpg

Now, switching on Tello he refuses connect those busy low channels, in this case Tello chooses channel nine. After switching off Deauther Stick you will get something like this:

tello fake by deauther.jpg

We got it !. As you know, if we were not using WIFI deauther Tello would have choosen one of the first free channels, surely channel three or four.

Now we only need turning this experiment into something more practical, but at least it has proven that the concept is valid.

Take into account is not a perfect tool. Sometimes it fails. I suposse "fake wifis" are not simultaneously created and sometimes Tello see a free channel "gap" spoiling the whole process.

I hope it helps.

raul
----
 
My neighbors's wifi names is like "ham_sandwich" and "bacon_egg". Guess he was hungry.

Back to topic, i checked what happens with my Xiaomi Nano Youth router extending tello's wifi:
Whatever I do it just picks ch1 and stays there. So if router is switched on first it will pick ch1 and Tello will pick ch6 and both keep their channels. If I switch on Tello first both end up on ch1.
I guess I can select the channel it uses but I forgot to write down the router admin password so can't check without going through a reset & reconfigure.

What I love about the Nano Youth is that it can be configured using a browser. Not this nasty chinese spyware MiHome. I haven't looked into the packet contents but MiHome is calling home all the time, and it tries to access files it should not. Not what I like on my main phone, another reason to get a cheap dedicated phone for flight control & related stuff.

On a side note: I am no expert in Wifi. But as far as I know multiple Wifi on the same channel don't cause that many problems because they "listen before they speak" (see Carrier Sense Multiple Access/Collision Avoidance – Wikipedia). Overall it just reduces throughput and increases latency, but you won't notice this.
It can become a problem if there is a wifi router nearby that has badly tuned antenna so doesn't notice an ongoing conversation and sends while the channel is busy, so Tellos whispers drown in this noise.

Bluetooth is different in that it does not / can not check for an ongoing wifi conversation but still interferes with it.
Could you elaborate on the X Nano Youth router? It's not portable is it? Do you use it for around home? I think it's discontinued as I couldn't find information about it.
 
Its a small and portable USB powered router that can also function as a wifi extender, see here

Its discontinued but sometimes available for $10 on ebay or CL
 
I think that the tello it's just a toy, no need to get too complicated. If you need more range than what an cheap extender can give you, you really need to consider upgrading to a bigger more capable device.
 
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I think that the tello it's just a toy, no need to get too complicated. If you need more range than what an cheap extender can give you, you really need to consider upgrading to a bigger more capable device.

I understand what you say, but believe me I'm not doing too much! I just wanted to report this information to the forum that maybe someone might be interested in.
For the distance, Porto Tello over 300 meters without problems, thanks to the extension with a parabola.
I understand that for many this drone is just a toy, but I don't see it that way ... without offense it's just my thought.;)

This was the only modification made to Tello to improve the cooling of two important components.

system overheating on landing
 
ok guys....I did not read the entire thread so bear with me as I share so hopefully useful real world experience.....mainly with a Spark.

im in USA and a very rural area

if I fly toward town my range drops....I believe the homes with routers interfering.

if I fly away over Forrest and farm land....oh my...1.2 to 1.4 is common....by stick or litchi

forget 5.8..here......

use 2.4....prefer to lock on Chanel...but still ok if it scans 2:4

very little WiFi over the farm and Forrest land.

I have a Titan command case that we are about to use with the P4 and spark.....

to do any thing more than educated guess work you need a 2.4 ghz spectrum analyzer....

im not talking about the app based analyzers......they just show the tip of the iceberg.....

RC immersion has a mini spectrum analyzer for Fpv racers that is far from communications grade but has use....it’s about a hundred bucks.....I have one and am waiting to calibrate it with a communications grade analyzer .....

it can tell you a lot.....

part 2 is your antenna......if it is not matched impedance wise....any power coming from controller or booster is to some degree bounced back into the controller.....that burns up the finals in your controller......and in my opinion a lot of the cheap amplifiers sold burn up fast because of this mismatch.....

you need to tune the antenna to match the controller.....that’s not guess work.....you need some device to measure the mismatch , reflected back to controller power ....

some people call these SWR meters....

I welcome those of you who have some experience with such equipment in a 2.4 or 5.8 real world environment to help bring me up to speed.

most of my communications background was at HF vhf and uhf frequency’s....

This isn’t ment to discourage anyone....it’s ment to encourage using proven instruments to fine tune our birds.
 
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