New app: TelloFPV for Android

[volate!lo]

Sorry, I probably hijacked a totally different thread... I was thinking about how to find a Tello that was MIA. I assumed from the reported results in the link that the trilateration using multiple samples did work.

.. and for the experimental app ... charge more, not less . Filter out the less serious people. It's a bonus to get early access to some neat stuff, and possibly even to participate in its evolution.

Trilateraion does work but not for Tello. For inflight trilateration you'd spend the first minutes of flight time to gather the samples required and you'd still get low accuracy. And for a Tello that is MIA you most likely won't have wifi connectivity at all. Otherwise it would be relatively easy to find.

Te payment approach could work. Maybe charge $50 for the privilege of being a guinea pig. ?

 

[leonav]

Ok, I did it !

My first 3D Tello photo was taken:

Creating aerial 3D stereoscopic images from TelloFPV photos

Ok, I did it !

My first 3D Tello photo was taken:

Creating aerial 3D stereoscopic images from TelloFPV photos
I have make models from the poi video with the TelloFPV appl.
See the screenshots

 

[raulvolador]

The problem is accuracy in the real world is so low, its just not worth it. Misalignments in drone direction, phone direction, distance and direction to drone, initial GPS position, etc all add up to a level where the accuracy of such a "lost drone marker" is like: "Your drone crashed somewhere northeast, or east, or maybe south of where your phone thought it was, or maybe not. Distance is somewhere within wifi distance from your takeoff point.".
...

Totally agree @volate!lo, trying to show Tello's position over a map would be cool but it's currently only a dream

Yesterday I updated TelloFPV to 1.12a release. It works OK. I enjoy four succesull flights into residential area excellent video quality and good range.

Remark excelent performance from Return To Home (RTH) when you run into troubles due low signal. In fact, for me first automatic turnig towards home point is enought for recovering signal and caming back home into manual mode.

I discovered you can shoot a photo and as soon download counter starts it's long way (several minutes) from 0% to 100% going back to video mode and forgive about it. Later you can query download status returning briefly to the photo mode. It's cool !

Another discovery I did concerns VPS accuracy. After contrasting many flights I realized when taking off from a high place, VPS is confused and reports shorter distances. In my case, taking off from a roof terrace ten meters above street level I got a consistent 20% shorter distance (at 120 meters VPS reports 100 meters). Curiously, errors are compensated between outward and returning trip. As a result when I land again over terrace distance is close to zero. I'M NOT COMPLAINING ABOUT TELLOFPV I know the way VPS works it's only Tello firmware internals related and it has nothign to do with TelloFPV app behaviour.

Raul.

 

[volate!lo]

Totally agree @volate!lo, trying to show Tello's position over a map would be cool but it's currently only a dream

Yesterday I updated TelloFPV to 1.12a release. It works OK. I enjoy four succesull flights into residential area excellent video quality and good range.

Remark excelent performance from Return To Home (RTH) when you run into troubles due low signal. In fact, for me first automatic turnig towards home point is enought for recovering signal and caming back home into manual mode.

I discovered you can shoot a photo and as soon download counter starts it's long way (several minutes) from 0% to 100% going back to video mode and forgive about it. Later you can query download status returning briefly to the photo mode. It's cool !

Another discovery I did concerns VPS accuracy. After contrasting many flights I realized when taking off from a high place, VPS is confused and reports shorter distances. In my case, taking off from a roof terrace ten meters above street level I got a consistent 20% shorter distance (at 120 meters VPS reports 100 meters). Curiously, errors are compensated between outward and returning trip. As a result when I land again over terrace distance is close to zero. I'M NOT COMPLAINING ABOUT TELLOFPV I know the way VPS works it's only Tello firmware internals related and it has nothign to do with TelloFPV app behaviour.

Raul.

This self-compensating "VPS drift" is actually not that surprising. Just imagine yourself in Tello's seat.
All Tello knows is altitude from takeoff position based on the barometer, some acceleration (but not speed) over time, and the speed calculated by VPS based on the speed some marker moves through the pinhole camera's image.

Taking off at 10m and gaining another 10 meter high Tello measures and reports 10m altitude using its barometer, but in reality its 20m altitude.

Now the VPS sees the ground moving through it's pinhole camera at a certain speed, but it doesn't know the distance of the ground, only the altitude over takeoff point measured with the barometer. Based on the movement, the (measured) 10m altitude and some trigonometry it calculates a speed of 5m/s when in reality the true speed is 10m/s.
I guess there is some compensation going on, based on the speed that is reported by the inertial sensors (integral of acceleration) vs speed reported by the VPS, and after fusing all the sensors Tello calculates a speed. That should be somewhere in between the 5m/s reported by VPS and the 10m/s reported by accleration sensors. Maybe 8m/s instead of the true 10m/s.


You can also see the same in reverse: take off at ground level, fly at 5m/s and then suddenly fly over a roof or some trees. Tello now sometimes reports insane speeds (and distances). If flying 5m above the roof the resulting speed is also different than if flying just 1m above the roof (because then the IR sensor reports the 1m hight and Tello knows its flying over some obstacle).

All in all Tello's VPS works best in pretty flat areas without many obstacles.

 

[raulvolador]

This self-compensating "VPS drift" is actually not that surprising. Just imagine yourself in Tello's seat.
All Tello knows is altitude from takeoff position based on the barometer, some acceleration (but not speed) over time, and the speed calculated by VPS based on the speed some marker moves through the pinhole camera's image.

Taking off at 10m and gaining another 10 meter high Tello measures and reports 10m altitude using its barometer, but in reality its 20m altitude.

Now the VPS sees the ground moving through it's pinhole camera at a certain speed, but it doesn't know the distance of the ground, only the altitude over takeoff point measured with the barometer. Based on the movement, the (measured) 10m altitude and some trigonometry it calculates a speed of 5m/s when in reality the true speed is 10m/s.
I guess there is some comensation going on, based on the speed that is reported by the inertial sensors (integral of acceleration) vs speed reported by the VPS, and after fusing all the sensors Tello calculates a speed of something in between. Maybe 8m/s instead of the true 10m/s.


You can also see that if you take off at ground level, fly at 5m/s and the suddenly fly over a roof or trees. Tello now sometimes reports insane speeds (and distances). Flying 5m higher than the roof the resulting speed is also different than if flying just 1m higher than the roof (because then the IR sensor kicks in and Tello knows its flying over some obstacle).

All in all Tello's VPS works best in pretty flat areas without many obstacles.

An excellent explanation, as usual, thanks @volate!lo

Thus you should increase about 20% all my range records performed from my roof terrace

Raul.

 

[volate!lo]

An excellent explanation, as usual, thanks @volate!lo

Thus you should increase about 20% all my range records performed from my roof terrace

Raul.

No, instead you should go into rural areas for range records. Makes for nicer videos anyway

 

[umanbean]

No, instead you should go into rural areas for range records. Makes for nicer videos anyway

Great idea!... this way we could see more classic "old Spain" architecture!

 

[simhaindia]

Found a strange issue

using tellofpv app
Tello gets disconnect in midflight although wifi signal is good tello is just 7m away from me.tellofpv shows phone in airoplane mode?

wifi gets stuck at obtaining ip address.

reconnection is never possible until tello is restarted.

Happened twice and tello descends with no connection after one minute and hovers till battery drain. luckily both the time tello was in right place.

i have to forcefully switch off tello.

there is no password set for tello wifi.

Pls give a solution

 

[volate!lo]

Found a strange issue

using tellofpv app
Tello gets disconnect in midflight although wifi signal is good tello is just 7m away from me.tellofpv shows phone in airoplane mode?

wifi gets stuck at obtaining ip address.

reconnection is never possible until tello is restarted.

Happened twice and tello descends with no connection after one minute and hovers till battery drain. luckily both the time tello was in right place.

i have to forcefully switch off tello.

there is no password set for tello wifi.

Pls give a solution

Has nothing to do with TelloFpv app but with your Android OS.

Your android is dropping the wifi connection to Tello. Of course Tellofpv can't do anything once the wifi link is gone.

The question is why does Android drop it? Do you put your phone into airplane mode for flying?

 

[simhaindia]

Has nothing to do with TelloFpv app but with your Android OS.

Your android is dropping the wifi connection to Tello. Of course Tellofpv can't do anything once the wifi link is gone.

The question is why does Android drop it? Do you put your phone into airplane mode for flying?

andriod os 8.1
For one flight phone was in aeroplane mode.
For other it was not.

So do you mean if the connection is lost once it will not be restored?

 

[volate!lo]

andriod os 8.1
For one flight phone was in aeroplane mode.
For other it was not.

So do you mean if the connection is lost once it will not be restored?

TelloFpv does exactly nothing with the wifi connection.
TelloFpv does not actively restore a lost wifi connection. Just like the Ryze app does not actively restore a lost wifi connection. Either Android does it by itself, or you have to do this manually.


The only thing TelloFpv does is open Android's Wifi dialog if you press the wifi signal image at the bottom. But that is just the same as going there manually using the system bar.


Typically this happens if the phone is not in airplane mode, or if you are near some other wifi (which your phone knows). Maybe "forget" the tello network and connect again. If it complaints about lack of internet connectivity open the message and click the checkbox and press OK.

 

[Pac-tello]

It is possible you have a wifi network with a strong signal that drowns out the wifi connection to the Tello. When the device disconnects from Tello it re-connects to the strongest wifi network you are a member of. If this happens you should ‘forget’ other networks or fly Tello away from possible interference.

 

[volate!lo]

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It is possible you have a wifi network with a strong signal that drowns out the wifi connection to the Tello. When the device disconnects from Tello it re-connects to the strongest wifi network you are a member of. If this happens you should ‘forget’ other networks or fly Tello away from possible interference.

True, that I forgot to mention!

 

[simhaindia]

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It is possible you have a wifi network with a strong signal that drowns out the wifi connection to the Tello. When the device disconnects from Tello it re-connects to the strongest wifi network you are a member of. If this happens you should ‘forget’ other networks or fly Tello away from possible interference.

But there was no known signal beside me and also I tried to manually connect by clicking on tello wifi.

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It is possible you have a wifi network with a strong signal that drowns out the wifi connection to the Tello. When the device disconnects from Tello it re-connects to the strongest wifi network you are a member of. If this happens you should ‘forget’ other networks or fly Tello away from possible interference.

But there was no known network in surrounding.

And manual connection by clicking on tello wifi network also failed at obtaining ip address.

I am thinking this is not phone issue as I even restarted the phone and tried re connecting but it failed.

Only after tello is restarted it is connecting.

 

[volate!lo]

But there was no known signal beside me and also I tried to manually connect by clicking on tello wifi.

But there was no known network in surrounding.

And manual connection by clicking on tello wifi network also failed at obtaining ip address.

I am thinking this is not phone issue as I even restarted the phone and tried re connecting but it failed.

Only after tello is restarted it is connecting.

This could well be a problem of Tello. Which firmware?


The only thing I do know is that its not related to the app, as the just doesn't control or monitor the wifi connection. It just uses the connection that is there (or fails if its not there).
It was a design decision in the early days to not mess with the Wifi (like aTelloPilot does) because this Wifi stuff is very fragile, and needs different programming approaches for different Android versions and even phone models. What works on one phone may not work on others, so I thought its best not to mess with this.

 

[Flydrone]

Today I tried to fly, it's ok! there have been gusts of wind between 14/20 km but I didn't dare to fly above 15 meters ....
I tried to fly away from me for about 50/80 meters and for my distraction I couldn't see the little Tello anymore! the display even if with high brightness, in the sun I was struggling to understand the direction of return ... the fear was the wind that occasionally blew on the 20km, so I made a RTH and that brought me back to Tello above me!

 

[umanbean]

the fear was the wind that occasionally blew on the 20km, so I made a RTH and that brought me back to Tello above me!

And that's amazing isn't it?... considering lack of GPS!

volate!lo has created an app that has transformed the Tello experience for thousands of us lucky Tellowners!

 

[volate!lo]

Today I tried to fly, it's ok! there have been gusts of wind between 14/20 km but I didn't dare to fly above 15 meters ....
I tried to fly away from me for about 50/80 meters and for my distraction I couldn't see the little Tello anymore! the display even if with high brightness, in the sun I was struggling to understand the direction of return ... the fear was the wind that occasionally blew on the 20km, so I made a RTH and that brought me back to Tello above me!

I do that on a daily basis (I never really care where Tello is in relation to me when I'm flying FPV). So far no catastrophic failures or losses .

 

[Flydrone]

I do that on a daily basis (I never really care where Tello is in relation to me when I'm flying FPV). So for no catastrophic failures or losses .

I usually prefer to always fly on sight, but today for the first time I lost sight of the drone and the RTH function brought me back my Tello! I have tried RTH many times to test this function or simply to automatically bring Tello back to me, but today without this function I risked losing the Tello with the wind .... Great app!

a part of my equipment on the field ...
I'm really fond of this little Tello !!!

I always leave with the protections ... I am sure that many people ruin the engines due to collisions with the propellers.

 

[raulvolador]

I found a new use for TelloFPV's Bitrate Indicator, the one shown when you check SHOW CORRUPTION INDICATOR into Video Settings.



I realized you can use Bitrate Indicator as a video link quality meter. That's very important when WIFI power indicator doesn't property work, for example when flying with Xiaomi Repeater onBoard, as I did into my last Tello mod. You can see more details here: Xiaomi Repeater onBoard Tello mod

Thanks @volate!lo for providing us such a versatile flying app.

By the way, Is there any scheduled date for launching next release ?

I think it adds some new exciting features, as Bitrate change shortcut and Region query.

All the best.

Raul.