Remotely switch on/off, auto recharge, precision land

[Hacky]

Hello makers and coders,

I would like to enable Tello for some more automated services. A similar idea was discussed already in the "wireless charging" thread, but not in depth.
Idea is the following:

1. Tello gets a control circuit that allows to switch it remotely on and off via a GPIO pin of an external controller. This signal could go to one of the 4 landing feets.
2. Tello gets contacts on it's "feet" that allow to provide 5V for charging. This power source should only be switched on when Tello is switched off.
3. Tello should be able to land precisely on these contacts

Regarding 1:
If it would be possible to "override" the built-in push button by shortening the contacts and if one of the contacts is already connected to GND, it should be possible to drive a transistor or Mosfet from an external GPIO pin to draw it down to GND.

This is just an idea - perhaps you already have other ideas or you already did some measuring.

Regarding 2:
The wires from the feet could be connected to the 5V lines of the Micro USB port. When Tello is switched of, this should automatically start the charging. When Tello is (remotely) switched on, the charging power supply should be turned off. It should be possible to combine that with "1.".

I found some examples for P-channel Mosfet based switches here: p-channel MOSFET switch | Newbedev

Regarding 3:
In order to allow Tello to precisely land on this "charging pad", one of the Tello EDU mission pads could be modified (or printed as described here.
For programmatically controlled Tellos meanwhile we know how to acces the downward facing camera, as described here). This could be used to identify markers like Aruco markers.


I would be happy, if others, who already spent some time on this or plan to implement this as well, could share their experience here.

 

[uncleVader]

I've been thinking about this problem and successfully got a Tello to charge from a cheap Qi-enabled charging pair from Aliexpress/Banggood/wherever. The USB-Micro pads are just small enough to attach to the bottom without blocking the down cam. I have been thinking about close-enough landings that magnetically align from tiny permanent mags on the feet. When I get time to complete, I will post something!

 

[Hacky]

Thanks for your reply.

What is the weight of your Qi-enabled solution?

 

[chabanG]

hi can you give more details of how you made that wireless charger? I'm interested in a similar project for school

 

[jerimiah797]

Have you seen this video? Wireless charging with 3d printed landing gear. (I did not make or try this, just found it with a google search... )

To view this content we will need your consent to set third party cookies.
For more detailed information, see our cookies page.

Accept third party cookies

 

[chabanG]

I have not, thank you sharing this. This will be very helpful.

 

[Hacky]

Thanks for the video.
Unfortunately this solution will not work in a fully automated scenario. Charging over USB happens only when Tello is switched off. Tello EDU with latest firmware also does not show up the WiFi when something is connected to the USB port. I guess, this happens also for the Qi Charger receiver.
Last but not least, the alignment is also not easier than with a contact based solution. So I see no value for the extra weight added by this type of charging solution.

 

[jerimiah797]

Yeah, one possibility might be to get creative with an ESP01 or something and hook it into the power button so you can have control over turning the Tello on and off independently (from another BT enabled device). Or maybe even use BLE or another sensor to activate the switch. And/or a software-controlled USB plug connect/disconnect relay. The possibilities are many.

Including the video I posted, there are probably at least a few other 'non-ideal' solutions, and if someone is okay with that, then I say go for it. You'll be able to say 'I did it', even if it's not the best solution. Either way, you'll learn a ton and hopefully have some fun. I've seen some interesting funnel-shaped landing pads /gear for other drones that can guide it into an exact alignment. Again, probably not ideal, but that shouldn't stop anyone from experimenting, IMO. Good luck!

 

[tellodronelover]

Hi guys, I am trying to spot welding the push button with the GIPO control for turning off the DJI Tello drone, but I don't have the datasheet of the button. Can anybody help?

 

[tellodronelover]

Can I use the python programming control to turn the DJI Tello drone power off?

 

[Hacky]

I do not see an explicit way to remotely shutdown / power off Tello. The SDK only provides a "reboot" command.

An indirect way for shutting down could be, to simply let it stay on ground for some time. If there is no ventilation, Tello will automatically shutdown due to overheating...

 

[tellodronelover]

Yeah, I knew that the way of turning off the DJI Tello is overheating, but how does it work? Is it has any sensor to trigger the power off? I am now trying to spot welding the button connection with Arduino to trigger the power on/off. The button seems like the tactile switch, if once we give a 1 signal to the DJI Tello drone quickly, it will turn off.