1. What is your job? are you the independent developer?
Actually, I am working for a mobile phone chip maker but I used to make some drones and apps as a hobby.
2. How long have you played drones and when did you know about Tello?
I have played drones for about 5 years, but I am enjoying to build drones rather than playing them.
I came to know Tello drone last march and I determined to buy it after watching the reviews on YouTube.
It was so stable and has excellent video quality than other toy grade drones.
And that it was also affordable ^^
3. Why you start to design this app, and how much time you spend on developing?
Actually I already developed a drone control app named BTCon4Drone for MultiWii based drones years ago.
It was designed for small drones with camera and several sensors like open source drones.
At first, I just tried to integrate Tello feature into the app but I came to know Tello could be controlled as a different way due to its stability and video quality.
So I branched it to aTelloPilot and added several features for Tello.
It takes about 3 and half months to develop aTelloPilot based on BTCon4Drone.
4. What is the hardest task of the developing and which part cost the most of whole developing?
As you know, there are no open information about Tello control except simple text command based SDK.
When I started to develop, there was no way to get the video stream with text command.
So I had to analyze the wifi packets between mobile devices and Tello.
I also decompiled your official Tello app to get more hints but it was hard to read due to obfuscated settings (ProGuard).
I spend most of the time to decode the commands and parameters and video I frame request rule was hardest to find when video packets were broken.
About flight log, I got many information from the TelloPilots forum.
5. What is the most satisfying part you considered in this app,and what is the users favorite part?
Face tracking is the user's favorite feature because the official Tello application doesn't support ^^
Actually the feature is not hard to implement because Google already released very good face tracking library.
Second favorite feature is "ReturnToHome", actually I do not use the feature often but I saw a comment from an user who made a flight long range with WiFi repeater.
He could fly Tello about 300 meters and he could withdraw it by RTH feature. When I saw the comment I felt very proud.
6. Can you give us some suggestion about our SDK、hardware and software?
About SDK,
SDK 1.3.0.0 seems good, now it can receive video stream and get several useful Tello state.
But there is no way to request I frame if the video stream is broken.
About Hardware / Software
I think it's better if compass sensor is applied for absolute orientation.
Currently Tello and user should be aligned before takeoff to match the orientation but it can be skipped if compass sensor is installed.
One more thing, I hope Tello equips hardware expansion slot for pluggable accessories like Parrot Mambo.
I think it will expand the Tello drone usages and it will make more fun.
And if you make your application can install plugins for the accessory, it will be great.
The Tello SDK connects to the aircraft through a Wi-Fi UDP port, allowing users to control the drone with text commands. The new SDK 2.0 allows you to develop Tello EDU further, realizing more AI functions such as object recognition, tracking, 3D reconstruction through programming, computer vision, and deep learning technologies.
If you need to know more about aTelloPolit App, please click on this link
If you want to know how to access Tello stream,please click on this link
If you want to program multiples Tello EDUs simultaneously using SDK 2.0, please click on this link