Tello extremely inacurate/wont follow code


We have programmed the flight paths in drone blocks, but the tello is not cooperating. It will skip over blacks, ignore them, etc.

The distances are obviously a little wishy washy without GPS but the drone is ust not registering parts of the code.

Anyone else having this issue?

Yes we too are having this issue

We used Tellos in our drones 1 class last year and they are very inaccurate. It is rarely repeatable and it has never been a good experience to code with them. When I heard that we would have to use them this year, I was very skeptical and, so far, it is the same, if not worse with the beta.

I agree, we are having the exact same issues. The Tello skips some blocks or executes all the things all at once and the flight path is not reproducable. Please let us know what to do, and if we are allowed to use something else like python with DJI tello library.

Any help is appreciated.

We have had luck with fully restarting the droneblocks app each time after aborting a mission. Failing to do this seems to cause a variety of different errors (including what was mentioned in this thread already)


Thanks for pointing this out. There is a current bug in the abort mission functionality that keeps the blocks queued up in memory. A restart is a good work around for the time being. I will follow up with our dev team to see what the status is on a short-term fix.

@coachharrison one thing I want to mention is that Tello is very sensitive to its surroundings. Good lighting and floor patterns are helpful for Tello to more accurately respond to commands. If there is poor lighting or reflective surfaces it may not be able to easily “see” the mission pads. There is also a limited range of visibility for Tello to see the pads and we recommend hovering no more than 5’ above a pad. I hope this helps. Let us know and we can troubleshoot further.

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Thanks for the suggestions! I never really thought about that.

Thank you for the suggestions!

Yes. We feel your pain! Our Tello team has spent endless nights aiming for reproducibility. Sometimes the happy Tello will comply. Then all of the sudden, no can do Brah! The manic Tello will switch to a different personality, go coo coo for co co puffs, and base jump while hovering over a pad prior to a near-successful landing mission, with full disregard for the loving students it’s leaving behind. Well, here’s what we have learned.

  1. Tello with its current programming control system is not ready for our competition objectives. Simply cannot program a robot that does not obey commands consistently. It’s rather discouraging to the students. As in FRC, we blame the Robot build team, not the programmers. =)
  2. Some consistency in just the beginning of the sequence is achievable if you shut off the Tello, restart Droneblocks, reload the program, and pray, before every program run. Yes, it’s time-consuming, but we don’t need to go home and spend any time with our family.
  3. Don’t run the battery below 50-60 percent. There are no “encoders” and the robot is simply running in “dead reckoning” mode.
  4. Must have good lighting. We have low ceilings and pad lighting is poor due to overhead lighting dead spots. We shine portable light sources on the pads and at times supplement with our phone lights during mission runs.
  5. Get ready to buy another Tello when the internal sensors meet their doom or the brushed motors start giving out.
  6. Pray again for good measures.
  7. Realize that it’s just a game and a first-world problem. Relax, and enjoy the ensuing comedy. Can be hilarious when the Tello Kamikazes.

Good luck and enjoy the game!

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I will say there is no need to buy a new tello after the motors die, I have saved quite a few by replacing the motors myself.

We are having the same issues with Tello and DroneBlocks.