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For the last couple of years (!) we have been discussing on and off about automatically flying the Crazyflie from a PC using OpenCV and a camera. We did a try a while ago using a PS3 Eye camera that wasn’t very successful. One of the issues we were having was detecting the distance from the Crazyflie to the camera. Another issue was a lag of about 1 second which made it impossible to control the Crazyflie using the video as input. So last week this discussion came up again and we finally decided to buy a Xbox360 Kinect. The image resolution is higher than the PS3 Eye and of course it has the ability to detect the distance from the camera to the objects it’s seeing.

Crazyflie and Kinect

The goal was to create a proof-of-concept application that shows that it’s possible as well as providing a stub for anyone that’s interested in doing more development. The application uses the normal image as well as the depth image from the Kinect to estimate where the Crazyflie is. This can easily be done by attaching a small colored ball to the Crazyflie and using a white background for flying. The images are processed and the current X/Y/Z co-ordinates given to a control loop. The control loop consists of thee PID regulators that will correct the roll/pitch/thrust that is sent to the Crazyflie to reach a X/Y/Z set-point in the image. The X/Y set-point can be selected by clicking the image or you can hold down the mouse button and drag it around. A cool feature that we would like in the future is to draw a geometric shape that the Crazyflie could follow. But there’s still a lot of work to be done with the control loop before we can achieve that.

After seeing the video you might be asking yourself where the James Bond theme music or the inverted pendulum is. Well, we are’t quite there yet and we will probably not even get near it. But still, this shows that the concept works. And for anyone that’s interested, it’s possible to do some basic trajectory planning algorithms at home with a Crazyflie and a Kinect.

For a more technical details have a look at the Kinect page in the hacks section of the wiki.

The first time we saw the video for the Leap Motion we instantly thought “Wow, we have to fly the Crazyflie with this!”. So finally last week a fresh Leap Motion landed on our desk and we went to work. We were really happy to see that there was an SDK for Linux. Leap Motion listened to the community that thought that an early release of the code was better than nothing at all. The API is very nice to work with and you can easily get metrics for you hand (like elevation and roll/pitch). So we created a Leap Motion driver in the joystick layer that replaces the normal input device, and it’s flying! We are going to be honest, at first it wasn’t that fun. It was more the concept that was very exciting. But as we flew more and more it started getting really great! There’s just something magical about it :-)

You fly the Crazyflie using a single hand. Thrust is calculated using the elevation of you hand from the sensor, so holding your hand higher means larger thrust. Pitch/roll is controlled by tilting you hand the same way you want the Crazyflie platform to tilt. So tilting your hand forward tilts the Crazyflie forward. Lastly the yaw is controlled by rotating your hand in the X/Y plane (around the Z-axis). For thrust/pitch/roll the control values are absolute, but for yaw it’s the rate that you control (just like the normal controls in the Crazyflie client).

As a safety mechanism the Crazyflie will only respond if the Leap Motion detects 4 or more fingers. So holding your fist above the sensor does nothing, but the instant you open up your hand you can start to control the Crazyflie.

The code for flying with the Leap Motion is still on a development branch but if you are eager to try it then have a look at the instructions in the hacks section of the wiki for documentation on how to get flying! The plan is to merge the Leap Motion code into the main track once we are finished with the development.

Crazyflie and Leapmotion

We are now all back from vacation, restarting the work on Bitcraze stuff. We are looking forward to play with the Leap Motion we just received…

The development is still going forward. Among other things the Android client development has greatly improved lately and we are hopefully getting closer to the first official binary release. We are also thinking of releasing a new version of the client and firmware as some functionalities and bug fix has been implemented since the last version.

After the second batch was finished we made the Bitcraze products available to distributors through the Seeedstudio Warehouse. Now we are really excited to see that our products have started showing up in distributor webshops around the globe. In order for our users to easily find local retailers we have compiled a list of distributors. There’s some lag between the time you start distributing our products until we get notified by Seeedstudio, so if you are not in the list of distributors drop us an email and we will add you.distributors

We finally got the time to clean-up the Crazyflie kicad project enough to make it publicly available.  It is not in a perfect shape but should be good enough to use and learn from. It’s a 4 layer board with signal layers on bottom and top and power planes in the middle. We have also uploaded the custom kicad-libs parts which should be placed in the same directory level as the kicad projects in order to make use of them, it also includes Crazyradio kicad parts.

It is released under CC BY-NC-SA license so you are able to use if for personal use, and please respect that. Please also give us feedback if you have some comments or find something that could be improved!

Crazyflie kicad snapshot

 

The Crazyflie project started as a competence project in a Swedish consulting company called Epsilon (now called ÅF). The first blog, Daedalus projects, was the competence-group blog. When crazyflie became more than yet another competence project we created our own website but Epsilon/ÅF graciously allowed us to still use the same server. We thank Epsilon/ÅF for the support but we thought it was time to be independent.

Since this week-end all the Bicraze public services run on our own server, the wiki and blog where the last pieces to move. There should be no noticeable difference except than we seems to have slightly more power now. We also are able to ramp up the server power in minutes if we ever get on Slashdot ;-).

Tell us if you see any problem or if the website suddenly became slow. Next step will be to improve the website front-page to make it more informative.

Last year we quickly hacked together a client for Android to show that it was technically possible to use the Crazyflie/Crazyradio on the platform. It worked, but it wasn’t very good. After that not much has happened, until now. Thanks to contributions being made by fredg02, Sebastian Sams and bug tickets from Sascha Heymann, the hackish prototype we did is now turning into something that is actually usable. It’s still under heavy development but there’s already some new features. Here’s a quick run-down of what’s been added:

  • An external controller can be used instead of on-screen thumb sticks
  • You can scan for Crazyflies
  • The same flight control settings that are in the cfclient are now available (i.e advanced mode, X-mode, max roll/pitch/yaw and thrust)

So the Android client works with phones and tables that support USB host or OTG. Anything else? Well, there just happens to be an Android platform that even comes shipped with an external controller…the Ouya! So if you have an Ouya and a Crazyflie you can just side-load and you are ready to go! Since we are used to the PS3 gamepad we had some issues getting used to the Ouya controller. If you have the same issue you can pair your PS3 controller with your Ouya and use it instead!

Once the software becomes more stable an APK will be released, but until then the repository with the code and issue tracker can be found here.

 copter_ouya

In order for users to be able to pilot the Crazyflie from platforms without a graphical user interface there’s now a headless client in the repository named cfheadless. It’s intended to be run the command-line and is still under development, but working.

The main reason it was made in the first place was to enable flying from the Raspberry Pi. The QT interface was very sluggish and it required all the QT dependencies to be installed. So the cfheadless client doesn’t depend on QT and doesn’t have a graphical user interface at all. For users to quickly get something working with the Raspberry Pi we prepared a pre-configured SD-card image that is based on the Raspian Wheezy. We didn’t remove anything from the image, we just added the things needed to fly the Crazyflie. It works out of the box with the Crazyradio and a PS3 controller. In order to switch to anther controller you will have to connect to the Pi and edit the configuration.

To use the image you have to edit the configuration if needed and then just connect your controller, power on the Crazyflie and lastly connect the Crazyradio. The cfheadless client will now automatically start and connect to the Crazyflie.

The image can be downloaded using this torrent or via direct download. The torrent is preferred since the direct download is limited to 6 simultaneous downloads. For more information on how to use the image have a look at the wiki page and if there’s any issues or suggestions drop by the project tracker at Bitbucker and add them. If you already have a Raspian image downloaded and running and you want to be able to use it with the Crazyflie then have a look at how we made the image or the hacks page with the original instructions.

Crazyflie and Raspberry Pi

The Crazyflie Nano Quadcopter kits, the Crazyradio and all of the spare parts are now back in stock at Seeedstudio. Like we mentioned before there’s been some changes since the last batch. We have added the Crazyflie Nano Quadcopter Kit and Crazyradio as separate products and updated the design of the motor mounts to better protect the motors. All the new kits include the new motors mounts as well as replaces the old motor mounts as spare parts.

Since we made the Crazyflie Nano Quadcopter Kits available during the spring we have gotten a lot of requests from other distributors to be able to sell it locally. So now we have made all our products available in the Seeedstudio distributor warehouse. If you are interested in retailing the products have a look at the Seeestudio distributor page or if you already have an account just log into the warehouse and you can find our products in the Robotics/Crazyflie category.

 

Crazyflie bundle

Crazyflie Nano Quadcopter Kit bundle with Crazyradio
Image ©Johan Jeppsson

 

 

 

So finally it’s getting warm and sunny outside (even in Sweden…) and it’s time to go out side and enjoy it while it’s lasts! This doesn’t only include flying the Crazyflie but also spending some time with our families and going on vacation. We have tried to plan everything so at least one of us is available to answer questions that might come up, accept pull-requests etc, but still it might take a bit more time than usual. And of course there will still be the Monday post!

If you happen to have some spare time during the summer and want a challenge, then have a look at the Crazyflie box… Have a great summer everyone!

Thanks to some of the motor mount feedback we have now managed to improve the motor mount a bit. It now has a longer extruded cylinder and a larger stop to prevent the motor form popping out when landing hard. This should add a bit more protection but it is still a good idea to do one of the mods described in the wiki for even better protection, especially when expecting to do some hard crashes.

Motor mount v2

Motor mount v2

The improved motor mounts will be available in the next batch of kits, which is still scheduled to be ready in the end of June, and also as a separate spare part item. For the next batch the Crazyflie kit without the Crazyradio and antenna will also be available for ordering.

On another note we are planning on modifying our webpage a bit. We feel that when new people visit our webpage they get no overview of our projects. So we are planning a nicer landing page with some images and more general information. We will of course keep the blog and also keep updating it at least every Monday. Aside from this we are also planning on integrating the forum and wiki with the blog and also have the same theme. After doing a quick test with the forum we are pretty sure our green/black theme will look good, but we aren’t that convinced about the wiki…. Let’s see where we end up. If you have any suggestions or comments about the webpage and our plans then  don’t hesitate to leave a comment below.

Lastly we have also installed TapaTalk on our forum. So if you use the TapaTalk app you can find our forum in the directory by searching for Bitcraze.