It’s been another week with lots of stuff going on. Shortly after the Crazyflies were delivered things really started to accelerate. Now there’s lots of cool stuff going on and we are trying to keep up :-) Here’s a few things from the last week.

  • People have started looking at the pressure sensor that is mounted on the 10-DOF version. phiamo is working on a hover-mode using the pressure sensor. There’s more information and code in this post.
  • Contributions to the Mac OSX install instructions have been made and they are now usable.
  • Another frame has been designed by bscott and is uploaded on Thingiverse. No doubt, next on the Bitcraze shopping list is a 3D printer.
  • The USB3 issue on the Crazyradio has been fixed so there’s a new version of the firmware. If you don’t have any problems with this then don’t update, because there’s a slim chance of bricking the radio (see the wiki page). The firmware is available here and instruction on how to update it are here.
  • A nasty bug on Mac OSX has been reported. When loosing connection to the input-device the output will become 100% thrust and it will not stop until the radio looses connection. This issue has been fixed in the latest version from the repository.

The Crazyflie Nano Quadcopter kit 10-DOF is out of stock again but there’s still some 6-DOF units left. We are currently planning the next batch but until then there will be a few more units (~50) that will drop into the Bazaar.

In order to have a better overview of which problems that have been solved and which still needs attention in the Support forums we are setting up some guidelines, which will be done during the week. So if you are hanging around in these forums or you want to get some support, then please have a look at the instructions.

If you live in the south of Sweden and you are interested in the Crazyflie drop by Javaforum next Tuesday (21/5) where we will be presenting.


It’s been an incredible week seeing people from all over the world getting their Crazyflies into the air!! We have seen videos of people doing crazy stuff we never thought of, 3D models of cases and frames on Thingiverse and of course a lot of images of people unpacking and assembling their Crazyflies. The wiki is receiving some well needed updates and everyone is helping out answering questions in the forum. It’s really great for us to see this project come to life after such a long time and as far as we can tell we have a lot of happy users, even though there’s still a few people struggling with issues.

Like we said last week, this is the first time we distribute the software/firmware/hardware widely and there’s a few bugs that has been found. We are currently correcting the most important ones and will post updates for the firmware and software once we fix enough of them. If you want to follow the progress drop by the bug tracker on Bitbucket for the PC-client, Crazyflie and Crazyradio.

We are doing our best to answer questions and give support in the forum, but there’s a couple of issues that we would like to highlight to make the assembly and usage easier for everyone. Please be careful with your new Crazyflies, they are not unbreakable.

  • Check for shorts after solderingAfter the motor wires has been soldered make sure to inspect for shorts and especially to the resistors, red highlighted area, in the picture as it can damage the digital voltage regulator. This will show up as that the blue LEDs wont light up and the other LEDs will be dim. To fix this the regulator U9 will have to be exchanged. It is the SOT23-6 package in the picture.



  •  The Crazyradio doesn’t work on USB3 ports but a fix is on the way. Until then the work-around is to use USB2 ports.
  • If the Crazyflie crashes upside down there is a chance the motor bearing gets depressed. There is a protection for this and that is to carefully glue a spacer between the motor and the propeller, similar to what we have done in the picture. That will prevent the propeller from pushing on the bearing but will instead be pushing on the spacer which will absorb the force much better. The spacer needs to be higher then the motor bearing else it will not work that well.


  • Loading an already existing input-device configuration in the PC-client does not work, the best is to start from scratch (see this issue). Also when configuring the input-device you will have to map all the axis and buttons before you can save the configuration (see this issue). For more information on device-input configuration see this page on the wiki.

Unfortunately the production of the new motor-mounts has been delayed and they will not be available for order until next week. But the kits that are currently in stock still contains a spare motor-mount.

Happy flying!!

Finally after more than 2 years of work on the kit, the first Crazyflie Nano Quadcopters are arriving at customers! It’s been a long journey with lots of ups and downs, and we are really happy that we managed to reach the goal (and on time).

For anyone who missed the pre-order, more kits will be available at Seeedstudio from the 6th of May. In addition to the products that are already there we will also make the motor-mounts available as spare parts. The 6-DOF and 10-DOF kits will be the same as for the pre-order (include the Crazyradio dongle) but the price for the 10-DOF kit will be updated to $179. Why the new price? Adding the two sensors turned out to be a bit more pricey then we thought.

Now to the technical stuff, here are some of the updates since last week:

  • Updated assembly with the new motor-mounts
  • Binary distribution page containing a brand new Windows installer for the Crazyflie Client (no need to install dependencies anymore) and also the latest firmware build for the Crazyflie.
  • A lot of smaller bug-fixes in the client and improved performance of the Crazyflie. So make sure to update to the latest firmware/client when you get you Crazyflie.
  • The Wiki is being updated (as always) and we are doing our best to catch up. We haven’t had time to set up the registration for the wiki, but if you feel like doing some editing drop us an email and we will set you up with an account.

Since this is the first time the Crazyflie and Crazyflie PC client are distributed there are bound to be bugs that we haven’t caught yet. So if you find any bugs it would be great if you wanted to drop by our Bitbucket page and report issues. And if you feel the urge to write some code, then have a look at how to contribute. There will probably be some bug reports and if not there’s always the wishlist.

We are always eager to get some feedback from our users so drop by our forum and let us know what you think about our projects or to pitch some crazy project ideas.

We finally got to measure the weight more precisely, just under 19g

Crazyflie weight with new motor mounts

Crazyflie weight with new motor mounts

A big thanks to Seeedstudio for making this possible. And to all of you, we really hope you enjoy your new Crazyflies :-)


It’s been a really hectic last couple of weeks and we are now very close to shipping the first batch of Crazyflies. It is a very big step for us so we would like to start by thanking you for your support! We wouldn’t be able to do this without your support and we really hope you will be pleased with the product and that it lives up to your expectations!

There are some updates to the pre-order kits which we hope you will be happy about. We have added two extra propellers in each kit. We have also updated the motor mounts to real moulded ones which should be easier to work with and more durable. They don’t require any glue, handles impacts and vibration better. The 3D printed motor mounts was not a viable solution when the volume increased so we have been working really hard on getting these ready in time. Since the new motor mount wasn’t available to order as a spare part during the pre-order, we have include a spare one in the kit for you.

Assembled Crazyflie with new motor mounts

Assembled Crazyflie with new motor mounts

The pre-order shipments will start as announced, on Apr. 25th, and finish on Apr. 30th. Orders will be shipped out in the order they where placed so second batch orders will be shipped a bit earlier with the last order going out on Apr. 30th.  Since Seeedstudio got a lot more pre-orders than expected, the first batch orders will need some more time for packaging and delivery and couldn’t all be shipped on Apr.25th, please understand.

Keep in mind that we are still doing development on both the firmware and software as well as continuously updating the wiki. So once you get your Crazyflie visit our page to get the latest updates and information on how to assemble the kit and start flying. Updating the firmware only takes a few minutes and you will get the latest features.

Thank you!

So, like we wrote last Monday, we are visiting Seeedstudio in Shenzhen, China. It’s been a great visit and we have gotten a chance to see both the Seeedstudio offices, the production and a bit of Shenzhen. And of course we also got a chance to do some shopping at the local markets. If you ever happen to find yourself in Shenzhen make sure to drop by the SEG Electronics Market, it’s a great place for electronics enthusiasts such as us!

Since we had some problems getting vacation all at once from our employers we decided to travel separately and overlapping each other a bit. Tobias left first and then me and Arnaud a couple of days later. After roughly 22 hours of travel we landed in Hong Kong and took the bus/train to Lo Wu to the Chinese boarder. Since I went traveling the week before and I couldn’t send my passport for the visa application we took the chance that we could apply for one at the boarder (after reading about it online). Turn out that it’s very easy to get a visa for the Shenzhen area (not all of China) at the boarder at Lo Wu. Took about 5 minutes and cost between ~130 yen. Just note that it’s not all nationalities that this applies to and the rules seem to change every once and a while.

Meanwhile Tobias spent his time visiting Seeedtudio and got to see the production. All the PCB assemblies was already done but the testing was running full speed. We use a simplified bed of nails test-jig that does the programming and tests voltages, current, battery charging, motor drivers etc. It is working very well and every Crazyflie plus Crazyradio takes about 2 minutes to program and test.

Visiting at Seeedstudio was great! We have been mailing and talking on Skype for the last 18 months with lots of people there and it was great to finally meet them in real life. Of course we got a guided tour around their offices which seems like a great place to work, lots of electronics everywhere :-) We also got a chance to catch up on the progress for the production. There’s lots of practical problems to solve when we scale up from only doing prototypes to full production, such as test-rigs for the Crazyflie.

After doing some research online we decided to head for the SEG Electronic Market to check it out and do some shopping. Inside it’s like a bazaar filled with small corridors and little booths selling all kinds of stuff. And this continues for 9 floors! On the first two floors you will find mechanics, electronic components, measurement equipment, leds, cabling… The list just goes on, they even had a small pick and place machine for prototype batches. Continuing upwards it becomes more and more computer hardware like graphics cards, mother boards, memory and hard-drives. These floors also have stuff like routers, cameras and tablets. Going even higher up everything is put together and you can buy laptops and computers. Its really amazing the diversity of things you can find, we even saw some cashier machines. Walking from the bottom floor upwards we really got the feeling that as you get higher things get more and more assembled. And everything is very cheap, for example we bought 300 pogo-pins in different variations for 100 yen (~16 USD), but expect the quality to be there after.

So what did we end up buying? Well, lots of stuff! We bought a lot of prototype stuff that we will use for the Crazyflie like cables, antennas, screws and batteries. And we also found a really nice USB microscope with a stand that does 500x magnification :-)

We uploaded some photos to our Picasa album for Seeed/Shenzhen.

Seeedstudio reception


This week and the next we will be visiting Seeedstudio for the first time so tonight we have been finalizing the travel plans! That might sound easy but it’s been a bit like solving a puzzle since we have to take vacation from our day jobs to go, and each one of us has slightly different vacations.

The purpose of the visit is to get a chance to finally meet everyone that we have been talking/mailing with during the last 18 months and also helping out during the final testing stage. And of course it will be really great to visit Shenzhen and fill our luggage with electronics for our trip back :-)

As for the production it’s still progressing according to schedule, we will post actual photos of the boards as soon as we see them :-D.

Map Copenhagen airport to Seeedstudio

Even though controlling the  Crazyflie with a PC is quite unique and permits a lot interesting things to be done, like controlling Crazyflie with a webcam or getting realtime telemetry, we have also been looking at controlling it with a, pc-free, standalone controller.

Current (unfinished) implementation of a standalone controller are using Crazyradio as a PPM to CRTP converter, a very experimental Android app, and using a raspberry pie as ground station. This week we finally managed to fly Crazyflie with an E-Sky transmitter:

Crazyflie standalone controllers

The transmitter is using a nordic-semiconductor chip compatible with our radio. The protocol is also well documented by dvdouden et al. It is using a power amplifier and uses a channel hopping scheme which makes the radio link quite secure.

Code to support this has been in the repo for a couple of week but a problem was that, by default, this transmitter was mixing pitch, roll and thrust channels which made the control of our Crazyflie nearly impossible (pitch and roll was changing by increasing the thrust ….). This week-end, we discovered two switches in the battery compartment, with which you can disable the mixing, and by doing that suddenly the Crazyflie is flying! There are still some work left to make RC transmitters works as good as a gamepad but the current source code is good enough to fly. Overall we have observed that a gamepad is really ideal to fly the Crazyflie in a fast and dynamic way. By comparison RC transmitter benefit by having more precision, mostly for the altitude control, but we are not used to it and it does not feel that ‘fast’ (our opinion).

As for the pre-order production, it is still going forward as planed. Testing of the first production samples  are finalized and now all the PCBs has been manufactured. The expected time of shipping is still according to the Seeedstudio Crazyflie product page.

We just received the first 10 sample boards from the production at Seeedstudio :-D


So far we got time to test only two boards and they are working. We have finalized the firmware, bootloader and production scripts so now it has really started :-)

Nothing new exiting about the production, it is still going as planned :-). Meanwhile we are focusing on stabilizing the Crazyflie firmware and its side projects.

This weekend we fixed a bug related to the memory allocation, which we have had a while now and that we never had time to track down. It kind of forced us to use heavier machinery so we decided to setup eclipse for debugging FreeRTOS threads and it happened to be very useful.

Since version 0.5 OpenOCD contains a rtos-awarness mode for FreeRTOS and, when painfully configured in eclipse, this allows us to observe the stack trace and the running state of all the tasks running on Crazyflie:


This helped us to track-down the bug much quicker and will greatly help us in the future. We also found a eclipse plugin, embsysregview, that enables one to show and analyse the peripheral register values, great little plugin!

The virtual machine will be updated with the debug environment and we will try to update the Wiki with the setup procedure.

The community interest for FPV flight made us buy a light weight analog FPV kits a while a go. We bought the 5.8GHz micro combo set from fpvhobby to do a first test. It took a little while to solder things together but it wasn’t that bad. We soldered the camera and the transmitter power to the VCOM voltage on the Crazyflie which is available on the expansion port. Then we taped the camera and transmitter to the Crazyflie and did a test flight.  The FPV kit is only about 3 grams which doesn’t affect the flight performances that much.

It was almost too easy, but as soon as we took off we noticed some vertical lines on the TV so maybe it wasn’t that easy. There seems to be some electrical interference, probably from the motors. Also the battery voltage drop generated by fast accelerations cuts the video feed after a couple of minutes of flight. We still think that there are some improvements to be done so hopefully it will work better in the future.

As for the production, so far it is still going forward as planned.

Finally an Alpha version of the virtual machine has been posted on the forum, you are welcome to test and report any problem/suggestion you may have :-).