Droneblocks Introduction to Tello Programming

WELCOME!

We are excited to have you here and look forward to sharing the capabilities of DroneBlocks with Tello. These lessons will demonstrate basic programming concepts and walk you through code examples of autonomous flight.

DroneBlocks is a free download and available in the iOS App Store, Google Play Store, and Chrome App Store. 

BEFORE WE GET STARTED

There are a few items to cover before we get started. Unlike other the drones that DroneBlocks supports, Tello is very unique given its small size and affordable price. Tello does not have GPS so DroneBlocks cannot make use of waypoints. This means that distances and angles will have some margin of error when progressing through the lessons. Do not be surprised when you give Tello a "fly forward" command with a distance of 60" and it stops at 55". In some cases it may fly a bit farther than the specified distance. Tello uses internal sensors to determine distances, which may not be as accurate as using GPS for positioning.

Tello works best indoors. Given its small size and lightweight, Tello may drift outdoors with even the slightest wind. We have completed many missions outdoors so it is definitely possible to fly outside, but your best results will be indoors.

While Tello can be viewed as a toy drone, we always recommend treating it the same as if it were a more powerful drone. For example, there is not much risk associated with flying Tello over students, however we still recommend not doing it. When you begin using DroneBlocks with more powerful DJI drones such as Phantom or Mavic Pro, you will want students to understand that these are NOT toys and can cause serious injury. If students learn to respect drone technology early on this will promote safety and advocacy for drones in education and industry.

LAUNCHING A MISSION

All of the lessons in this course will consist of using DroneBlocks to program an autonomous mission. The connection and launch sequence must be exact so we have provided a list, video, and printable image of this procedure. Let us go through the steps here so you understand the process.

1. Make sure you review your code blocks and understand the intended behavior of your mission

2. Power on Tello and place on a flat surface in an open area indoors.

3. Double tap your home button and go to Settings > Wifi

4. Tap on the Tello, which will create a hotspot that will look similar to: Tello-XXXXXX.

5. Double tap your home button and return to DroneBlocks

6. Click "Connect To Tello"

7. Now that you're ready to execute your mission click the "hamburger" icon. (It is the blue icon with three lines.)

8. Click "Launch Mission".

9. Watch the magic happen!

Here is a video overview of the connection process:

TROUBLESHOOTING

As with any emerging technology there will always be a few bugs and problem-solving opportunities along the way. We will cover some of the more common issues that we have run into while testing. In some cases the WiFi connection between your mobile device and Tello will drop. This means that DroneBlocks can no longer issue commands to Tello. Do not panic if this happens. Tello will execute the last issued command and then hover in place. At this point you can toggle into your WiFi settings and reconnect to Tello, then open the DroneBlocks app again and resume the regular Tello connection process.

In rare cases Tello will stop responding to commands and will hover in the air. You can close DroneBlocks and switch to the Tello app to regain manual control. If you still are unable to connect, the great news is that Tello has an internal battery threshold. Once this gets to a critical state Tello will land automatically! These issues do not occur often but it is important you are aware of these matters as you progress into the world of programming with Tello.

LET'S GET STARTED!

Once you complete this course you will be well-prepared to dive into our more advanced introductory course, which instructs how to use DroneBlocks with DJI Inspire, Phantom, and Mavic Pro drones. That is where the power of autonomous flight really begins!

Good luck and we hope you enjoy this course. If you have any questions or would like to share ideas, please join the discussion in our Facebook group:

https://www.facebook.com/groups/droneblocks

Let's get started!