Updated: Open-BLDC and open source Quadrocopters

Hi ho everyone!

Today I will write a bit about a “little” project I started recently. It is called Open-BLDC.

As I was writing my Diploma thesis I got involved with the Quadrocopter Community. There are some different projects and companies producing, selling and developing these small alternatives to helicopters. I really love these things.

There is only one really open source Quadrocopter, namely UAVP. The source is GPL but as far as I know you can not get any hardware anymore. The board schematics is somewhere in the repository. But still it is no more under active development and the code is pretty outdated compared to other projects like Mikrokopter.

Talking of Mikrokopter, it is an amazing project with a really amazingly big community. The problem I see there is the License. It is some strange proprietary license. I don’t want to get into the legal stuff here but it just feels wrong. Read it yourself for example here (sorry that it is only in german, it is not my fault ^^). The other thing that disturbs me is that you only get the ready product. You can not follow the development because the development branches of the code are not available to the public, so getting involved is very difficult. (yes I know there are branches of the code of other people in the repository that are doing their changes … but still) (I will for sure get bashed for calling Mikrokopter not properly open source … try to convince me ^^)

There is another project that grew out of UAVP, called NG-UAVP. The guys are working hard since 1.5 Years on their hardware and software. And as I asked them, they will probably release their source under GPL and the hardware under CC-NC. That would be awesome!!! But they want to have something really working and stable before the first release. Hopefully they will release it soon and stick to that licenses. (yes it is not completely sure :( )

Anyways. I really would like to have a completely open source project from the license to the way to develop everything. One thing that is a basic part in the current Quadrocopters are Brushless DC Motor controllers. There is no open source one anywhere. So hoping that UAVP-NG gets released under GPL I decided I should start with the controllers. If NG-UAVP fails to release under a proper license and organize the development so that everyone can contribute I will move from here to the IMU and controller.

Enough said. I started up the free version of Eagle (another missing thing in the open source is a really usable pcb cad software) and created a first shot at the schematics. After that I uploaded it to GitHub (and another place where open source is lacking, a good web interface to GIT, I really would prefer to have the interface installed on my own server). Not long time after that MarcusBec from the #uavp channel on Freenode took a look at it and told me that many things were just bullshit, and what I should do to make the design better. I am very thankful for that! So I already have one very major contributor to the project! That is how Opensource works. ^^

Now it seems that the schematics make somewhat sense. The controller pretty high end, using drivers for the P-MOSFETS and three rows of them. The microcontroller is an Atmega168 which makes a lot of space for code. Three interfaces are available for now, PPM (standard interface used in modelling), Serial and I2C. In the future I plan to add Can-bus too, for more robot centric applications. Currently I am working at making a PCB design, and hope I get it somewhat useful.

I am still looking for feedback and ideas. Check out the repository at http://github.com/esden/open-bldc and take a look at it. Perhaps you find something wrong and/or worth cleaning up. If you just have questions, don’t hesitate to contact me too! It is Open Source after all!!! :)

Cheers Esden

Update:
I got informed that my information about UAVP was wrong. The boards of the original project are still available from http://lipoly.de/ and http://www.quadroufo.com/. The source is also still under active development also by its main developer Wolfgang. So it may be a viable basis to work on for a really open source quadrocopter after all. But thankfully is open-bldc still no wasted time, because there is still none, at least to my knowledge, open source bldc useful for quadrocopters out there. Sorry for the mistake here I will research my information better next time!

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