Tello camera mod for fpv

ph2t · Apr 8, 2019

I have never been a big fan of the angle that the tello camera is set to. I'm not a big selfie/photos user of the tello and like to fpv fly it more often than not.

The angle of the camera is tolerable in normal speed mode but in fast mode the angle that tello flies at means the camera is effectively looking at the ground.

So I ripped it out and cut out a section of the front chassis. lol...

I cut the plastic sides off the camera, in the pic below you see the original on the left and the trimmed down camera on the right.

I think it sits quite well. The angle of the camera is loosely aligned with the flight angle of the tello. This way I can see what's coming head on.

Hot glue is the best thing. I used it to hold the camera in place.

I'm happy with the mod. It works well. The test video below shows the camera in action. It is a windy day here today so the tello got blown around a bit. I'm using some fpv goggles and flying with the Betafpv cam mod as well to compare.

Fun!

Kyle Knox · Apr 8, 2019

Brilliant man! Thanks for sharing that.

ph2t · Apr 9, 2019

No worries...

Sometimes I don't know if the fun is flying or modding! lol

In the end I found the intense zoom like focus on the tello camera just not suited to the task of FPV.

So I removed it entirely!

I also installed a 200uF low ESR capacitor across the power line from the batteries to the camera. I am hoping to reduce some of the noise you see in the video I posted in this thread.

Below you can see the yellow capacitor sitting on top of the connector for the original tello camera. I think the filtering with the capacitor holds promise. Brushed motors make a lot of noise and I'm sure the tello circuitry has it's own filtering installed. Given that the fpv camera is connected straight to the battery power it is not getting any filtering from the tello circuit.

I'm also trying out some antenna mods (yes another one!). I have disconnected the stock antennas and run some coax from the circuit board (see my tello PCB reference thread for where to connect an external antenna) to the top panel and have mounted them there.

A few things to note with the antennas.

I have gone for 1/2 wave length at 2.4 GHz, that is approx 61mm per antenna.
I don't have the correct lengths in the test setup as the ground shield in the coax was cut a bit short, the antennas start flat on the chassis before going into a vertical orientation. I need to fix this as the antenna should only be vertical and not a right angled shape (not for a whip style antenna anyway).
I'm trying to keep the two rX antennas at 90deg to each other - again currently not perfect.
The tello circuit may have been "tuned" for the shortened length of the stock tello antennas - adding a different length antenna to an already tuned circuit may reduce performance and not improve it. So far I'm seeing good range at over 100m in very noisy wifi areas.
I am testing this antenna arrangement side by side with a stock tello - I don't have android though so I can't use the TelloFPV app to check RSSI (wifi signal strength) accurately.