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TelloFPV + GameSir T1s - Strange Issue

StubbornSwiss

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Greetings!

I have my Tello hooked up to a T1s via OTG, and using TelloFPV. I have been using this set up for a little while with no issues.

Today I do a flight, no issues. The next flight, about 2 minutes in and the stick input is almost non existent. What I mean is that even with full right stick forward, in sport mode, the Tello is getting way less forward pitch than even in Video mode. This happens in all axis.

Since I have the T1s set to student, and the Onscreen as master, I try to control in with the onscreen sticks, but get the same response.

I land the Tello, shut down and start up again using the default Tello app and onscreen sticks, and everything seems to work ok. I try again with the TelloFPV + T1s, and I get the same issues.

Any advice would be greatly appreciated.

I've included a screenshot of my control set up, which is the same for all axis including throttle.

Thanks.

Screenshot_20200102-111250_TelloFPV.jpg
 

volate!lo

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Is this only for pitch & roll or also yaw & throttle?
Do you know if the red dots inside the onscreen joysticks were roughly where the grey ones were (with a bit delay as these aren't updated in realtime)?
 

StubbornSwiss

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Is this only for pitch & roll or also yaw & throttle?
Do you know if the red dots inside the onscreen joysticks were roughly where the grey ones were (with a bit delay as these aren't updated in realtime)?

Hello Volate!lo...... and thanks for your response.

1/ The issue was mostly with pitch and roll, and not so obvious, if at all, with yaw and throttle.

2/ The red dots were behaving they way I believe they were supposed to behave - with sticks centered, they were in the middle, and with full throw, the dots also showed full throw. However, the grey circles do not move. I have gone back and looked at a screen recording, and see that at the very beginning of flight, the grey circle moves briefly, but then stops moving. Are they meant to move together (with a bit of lag)?

I am testing this again right now, with just the controller and TelloFPV, and still the grey circle does not move when I use the sticks, but moves when I use onscreen.

Please advise.

Thanks.
 

volate!lo

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The grey circle represents the onscreen thumb position. These do not move for external controllers, only onscreen.

The red circle is the command that is sent to Tello (as said, not exactly in realtime but with some delay). That is the position of the currently active input "stick" (onscreen, external controller, or autopilot) after all filtering has applied: expo, rate, deadzone, rate_limit, etc.

The red dots are exactly what is sent to the drone, there is no exception to this rule. So if red dots were at the maximum, and Tello slows down, this is done by Tello and not the app.

Tello itself filters pitch & roll in lower altitude. This is not the altitude displayed (which is relative to takeoff) but true altitude above ground as measured by the IR sensor. If you are flying over a table and such, you will experience that Tello becomes sluggish. Just like it does shortly before landing.

If you were not flying over a table or chair or something then I'd suggest to check the IR sensor. And test both apps in exactly the same condition and the exact same spot again.

TelloFpv doesn't contain any code that could slow down tello by itself. The only code that slows down is by reducing rate setting or applying rate_limit, but both would be shown by the position of the red dots.
 
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StubbornSwiss

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OK...... very good. Thanks for that explanation.

I was actually flying outside when I noticed this, but thinking about it, it could have been when I was at a lower height.

Do you know approximately at what height agl the Tello filters pitch & roll inputs? Would be interesting to know.

As soon as the skies clear and the sun comes out and the ground dries :cool: , I will fly again and report back.

Again, many thanks!
 
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volate!lo

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Hard to tell, maybe 1.5m above ground (or tree, table, car, roof) it becomes noticeable.
The fact is that this happens with all apps if tested in the same conditions. If tellofpv behaves different there is a problem waiting to be fixed but I don't think so.
 
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