Category: Random stuff

It’s always fun get a change to meet fellow geeks/makers so during this fall we will be holding two presentations, first in Denmark and then in Belgium. They will be held at CIID in Copenhagen in October and at Devoxx in Antwerp in November. If you are close by then make sure to come by and say hello!

Here are the details:

If you don’t have the possibility to attend any of these and still want to hear us speak, have a look at our presentation at Oredev we did last fall or at the video from Devoxx after the conference. If you watch our old presentation, then pay attention at around 42:00 when Arnaud flies a Crazyflie into my forehead… It was just a matter of time before it happened :-)

If you have any suggestions on conferences/events were you would like to see the Crazyflie then leave a comment below.


It’s been a week and so far no-one has decoded the complete message (at least not decoded it and followed the instructions…), Pär has made a great start with “first” but there is more to it ;-).  So as promised here’s more clues. The message is 320 bits long and the bits are organized so they form a square (i.e the rows are directly underneath each other). That together with the clue we gave last week should make it a bit easier to decode. And if you need some motivation to get decoding, there is a reward included with the instructions :-). Edit: The reward was clamed by Joerg, congratulations! For anyone that still wants to try and solve it, don’t look in the comments. You will find the solution there :-)


One late night many months ago, we had a great idea! While finalizing the design of the Crazyflie box we decided to include a faint binary pattern in the background on the box. Taking a closer look at the box you will probably see it. After looking at it for a while you might notice a pattern emerging. The pattern reads 1011 1100 which equals 0xBC in binary, well most of it anyway. In some part of the code we decided to insert a message. We placed it in a way so it would be “easy” to notice the break in the main pattern. Now, this was well after midnight and we didn’t foresee all the problems that might occur.

Fast forward a couple of months and we get the first box from production in our hands. Turns out the binary pattern wasn’t as crisp as on the computer screen (doh..) and that it was shifted a bit from where we originally place it. To make things even worse the design had probably been panellized and the pattern wasn’t in the same place on all the boxes. This would never have caused any problems, except for the code that was hidden there…

We forgot about this for a while, but then we finally posted something about it. Then we sat back and waited for it to be found. But nothing happened. So we decided to finally sit down and try to decode it from scratch. Turns out that it takes longer to find and decode than Neo took to decode the code in the Matrix…. So we decided to make it a bit easier :-) Below is a scan of one of the boxes with a little Gimp-magic to improve the visibility. If you start looking at the 0 above the “y” you will probably find something interesting. It’s not easy, so if no-one finds it by next week we will keep giving clues.



The past weekend marks the two year anniversary of Bitcraze, the company we founded to manufacture and make the Crazyflie Nano Quadcopter kit available. Even though there’s been a lot of hurdles along the way we finally made it all the way to our goal! It’s been a great year with lot’s of fun things happening like finally testing the pre-seriesvisiting Seeedstudio in Shenzhen, seeing our empty forum filling up with active users and most of all seeing what users are doing with their Crazyflies. Thanks for supporting us!

Our first year with Bitcraze was spent doing lots of development, design, testing and sourcing. This year has been spent on lot’s of planning, administration, support and preparing for a release. We have said this a few times before, but it’s worth saying again: The easy part was getting the Crazyflie to fly, the hard part was manufacturing and releasing it. Having a company, website and production takes a lot of time. We are really happy with our co-operation with Seeedstudio, without them taking care of production/orders/sourcing/etc. we wouldn’t have had any time over for development.

One of the questions we were asking ourselves before Bitcraze was how our development would be affected when we suddenly had users using our hardware and software. Back then we basically did what ever we felt like doing, as long as it took us in the general direction of making things better. The client and firmware would suddenly be incompatible for a couple of weeks. If we needed to modify the hardware we just had 3 Crazyflies to patch. Sometimes we would just get fed up with everything and spend weeks doing other projects or going outside to smell the fresh air and get some sunshine. Having users and manufacturing a product changes things. It’s a great (and oddly bizarre) feeling seeing users assembling and using something that we have designed and worked on for so long. Even though we have spent years working with product development as contractors, we have never really seen or communicated with the end-users before. So in order to make this work we have spent lots of time discussing how to do things. That includes everything from naming conventions and work division, to how to organize the wiki and when to build new releases of our software. We once spent a whole night discussing how to name our products internally (like BC-CFK-04-A). Even though things are better now, there’s still room for lots of improvements.

So what’s the plan for the coming year? To get more development done! By now we have done most things for the first time, so hopefully the next time it won’t be as much work. Now that the summer is over and we have cleared our backlog of administrative tasks, we are hoping to get some momentum again. We will also try to find more fun things to do and to broaden the usage of the Crazyflie platform, like the Kinect and Leap Motion work, so that users can keep exploring and developing new things.

Crazyflie with candle

The image is actually the same image we posted last year when Bitcraze turned one. We are now one year older and wiser, which means we know better then to attach a lit candle to a LiPo battery and try to fly the quadcopter :-)

This Monday post we are devoting to the community development and we will try to give a short summary of what is going on there. We recently haven’t our selves had that much time to help out with this development, something we intend to change, so all credit goes to the community!

  • A port of the OpenPilot CC3D firmware to the Crazyflie done by webbn. Still under development but video already shows promising results.
  • Altitude hold functionality which is being developed in parallel by many, omwdunkley, phiamo, et. al. We hope we soon can contribute to this as well.
  • Improved thrust control which is being discussed a lot and hopefully we will soon see some ideas realized.
  • A Ruby cfclient written by hsanjuan.
  • The Android client with a lot of work from derf and sebastian.
  • The FPV implementation driven mainly by omwdunkley and SuperRoach. Omwdunkley has made an awesome HUD (Heads Up Display) which we hopefully sometime will see integrated into the cfclient. Check out the video!
We have probably forgotten some of the great development that has been going on recently and if that is the case please write a comment about it and we will update the post with it.

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

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.

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.

It’s been yet another week with lot’s of ideas, contributions and discussions. Here’s some of the things we’ve seen the last week:

And of course thanks to everyone that keeps updating the wiki and helping out in the forums!