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WIFI reflector for improving Tello range using Xiaomi WIFI repeater

raulvolador

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I read people using home-made wifi reflector for improving Internet WIFI coverage into their home routers:

You can use aluminum foil to strengthen your Wi-Fi signal

Trying to improve Tello's signal an range I built my own Windsurfer WIFI receiver using aluminium foil, glue and cardboard. I followed this web tutorial:

How to build your own Windsurfer Antenna

See results:

windsurfer wifi relfector.jpg wifi reflector xiami repeater hole.jpg wifi reflector xiaomi repeater assambly.jpg tello wifi reflector.jpg tello wifi reflector xiaomi ready.jpg

I tested my WIFI reflector attached into Xiaomi WIFI repeater. I was very excited but test results have not been very good.

I flew the same route twice, with and without WIFI reflector. Both fligths into an urban, crowdy WIFI environmentet.

I noticed an slightly improved signal strenght, a little better image quality and more signal bars, but range is quite similar.

In my first flight Tello was oriented forward. I could flew 140 meters away without reflector and 170 meters with reflector. That's a 20% range improvement.

In my second flight attemp Tello was oriented backwards (towards me). I could flew 200 meters away without reflector and 210 meters with reflector. That's a barely 5% range improvement.

EDITED: in other flights I have achieved improvements of up to 33%

Take into account you must flight right in front reflector. WIFI coverage is worse on the sides and null in the back.

In conclusion, for me not always worth it worth using a wifi reflector, but why don't test by yourself ?
 
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raulvolador

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Hi,

Yesterday I decided to gave my homemade WindSurfer antenna reflector another try.

I flew into an urban environment, high wifi interference. Xiaomi wifi extender with attached WindSurfer reflector placed at the roof terrace abour 10 meters hight and pointing in the direction of the Tello's flight. App used is aTelloPilot. Tello pointing in the direction of the flight, away from me.

My results:

Flying without windsurfer reflector I got a 133 meters range

tello with xiamomi.jpg

Fying using windsurfer reflector I got a 177 meters range

tello with xiamomi plus windsurfer reflector antenna.jpg

That is a 33% range improvement. I also noticed an stronger video signal. I got an extra bar into aTelloPilot four-segments Wifi strenght indicator for entire flight. Also a more stable image and less frame lost. In general, a feeling of more flying security.

But it is necessary to fly in the direction in which the reflector points, so the refector is only useful if you know perfectly where you want to go. You can see in this attached graphics how signal is amplified only in one direction:

Parabolic-Reflector-Antenna-working.jpg
6inch_plot_vert.jpg

Wifi reflecor is also bulky and fragile so it is only useful when you fly from home or you are looking to beat a distance record ;)

You should try it to draw your own conclusions.

Raul.
 

Flydrone

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Thanks! How are the little feet on the back of the antenna made?
Hi, I'm sorry if I answer you just now ... if you mean the legs to hold the parabola folded in half moon, these are not there, everything has been obtained from a bell container for DVD.
Behind the antenna there is a small sponge support with double-sided adhesive tape.
41ZVUImTYoL.jpg
 
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Walleye

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Hi, I'm sorry if I answer you just now ... if you mean the legs to hold the parabola folded in half moon, these are not there, everything has been obtained from a bell container for DVD.
Behind the antenna there is a small sponge support with double-sided adhesive tape.
View attachment 3543
Thank you! How’s it working?
 

raulvolador

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I have yet to try ...
I wish you good luck.

Take into account you didn't build a parabolic reflector, your invention it's much an a half circle reflector. I'm not sure about it's capacity for concentrate waves into a focus point :unsure:

220px-Conic_Sections.svg.png Focus-balanced_parabolic_reflector.jpg

Please, keep us informed abour your test.
 
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Flydrone

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From the first field test, I did not test the repeater well due to gusts of wind, but at a distance of 80/90 meters I had a fixed signal of 90 dB in TelloFPV. (consider that flight only in the fields away km from wifi interference and more).

I wanted to do something like this as optionals for dji radio ...
 

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Walleye

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I wish you good luck.

Take into account you didn't build a parabolic reflector, your invention it's much an a half circle reflector. I'm not sure about it's capacity for concentrate waves into a focus point :unsure:

View attachment 3556 View attachment 3557

Please, keep us informed abour your test.
How “parabolic” do these reflectors have to be? Aren’t they pushing the signal ‘out’? I suppose the signal does have to return as well to be sent to the RC. What if the reflector was placed on the extender? That’s supposed to be placed some distance away from the RC. Do you think it matters? Tx.
 

Donatello

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hi guys, I think than 90db is the signal level between you and the xiaomi wifi+ because the wifi of your smartphone is connected to it, so never will lose signal....
 

mbane78

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Today I made a parabolic reflector for Xiaomi repeater.

I made it on a 3D printer and used copper foil for reflective surface.

It's mounted on my old lighting/flash pole (~2.5m height) - I just hope I won't catch any lightning with it in the field.

Now all I need is some nice weather without the rain to test it.

1.jpg

2.jpg

IMG_20200128_142110.jpg
 

mbane78

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I did a little testing today, with the repeater and reflector.
I had a strong 3.6-3.7mbps video at 100m:

100m4mbps.png

At 160m I still had good video quality, around 3mbps:
160m3mbps.png

At 220m I had ~1mbps, but had no problem transfering pictures at high quality to the phone:

220m.png

This is the distance from Google Maps:
GE.jpg

The max distance for today was around 250m, it was reporting wifi interferance, I don't know if it was from powerlines or wifi signal from the buildings.

Since I was alone and there was wind today, and had to fly in sport mode all the time, I decided not to push it any further.

But I was delighted to see that in 100-150m range and 30m altitude I had a very good video (3-4mbps) and had no problem with controls. :)

Looking at the pictures, Tello was pretty far from me, I am just a tiny speck in the picture, without the GPS I quess it's easy to lose it if something goes wrong, as I could not see the drone.

me.jpg
 
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