RaceFlight One source code has been published and what does that mean

In the beginning of time, there was MultiWii and it was good. But then times moved on and 8bit ATmegas were end-of-line for flight control. So, Baseflight was created. In the beginning, it was supposed to be only a MultiWii port to support STM32f1 flight controllers in a for of Afroflight Naze. And it was good for a while. But the guy that was running this show turned out to be a prick and one of Baseflight developers forked everything and called it Cleanflight. One might want to say "Hail Hydra" but let's try to be serious here.

Anyhow, everything was great again. No pricks anywhere and Cleanflight was growing. People started to fork Cleanflight. Betaflight, INAV and Raceflight were created. No problems anywhere, one big happy family.

It did not take long for things to change. Someone decided that he can make money by making code closed-source and run only selected, sold by them hardware. It was RaceFlight by the way and this is a reason I'm not writing much about them. There real problem is that you just can not make an Open Source code under GPL license Closed Source just like that. It is virtually impossible since all commiters would have to agree to that. All of a few hundred. Good luck with that. INAV tried to change license once (and still be Open Source) and it failed. Few devs just said no. End of story.

Back to Raceflight. When in late 2016/early 2017 Raceflight went Closed Source. Some devs decided to check this and that, decompiled RF firmware and compared that with CF/BF. Surprise, surprise, decompiled code for gyro initialization looked exactly like in CF/BF. Raceflight was violating GPL license! They had no rights to close the code of Raceflight. Period. RF team defended themselves as they could but IIRC finally published source code for Raceflight (not RF One) like GPL required. Joshua Bardwell did a video on that topic you might want to watch BTW.

You might think this is the end of a story, but not. Raceflight announced RaceFlight One and claimed that RaceFlight One is 100% their doing, rewritten and does not contain absolutely no code from Baseflight/Cleanflight/Betaflight. So it does not fall into GPL at all. They were more less believed and most of pilots forgot about the whole thing.

Until yesterday. Because yesterday, Kalyn Doerr aka rs2k (one of creators on RF) published the full source code of Raceflight One on GitHub and posted something interesting on Facebook too:

(…) I don't want to say much publicly right now. I have kept quiet as I have been in fear for my safety for some time now. Over the last several months I have documented Preston Garrison's business dealings as he has tried to keep me away from the business. I have had no success in reasoning with him. I created it originally to share with the community and I have poured my lifeblood into it. It will not die here. I am RaceFlight.

Pretty scary, isn't it? Drama and stuff. But what happened is that RF One source code is on GitHub. Take it while it's fresh since it might be removed due to DMCA soon.

Let's leave the drama and see what mentioned Prestion aka proggod posted:

Well apparently Kalyn decided to release our code to the public without consent from me. I have no idea what his intentions are, or why he would decided to do this, last time I communicated him he was working on his home life. I can say he doesn't own the code, and it certainly can't be licensed as GPL, especially since he was not the only contributor to the code base. (…)

In other worlds "_I have no idea what happened but this code is private and GPL does not apply". Well… Betaflight community decided to check again an they found out something very interesting:

//TODO REwrite this better
char *ftoa(float x, char *floatString)
{
    int32_t value;
    char intString1[12];
    char intString2[12] = { 0, };
    char *decimalPoint = ".";
    uint8_t dpLocation;

//TODO REwrite this better is nothing strange. But, exactly the same ftoa implementation can be found in Cleanflight, Betaflight and INAV source code. And by exact, I mean exact. not similar. Exactly the same. It was committed by hydra in April 2014 under GPL license. And that means one thing: whole RaceFlight One is GPL. This is how GPL works. They did not rewrite it from the scratch, they took some elements of GPL code and continued from there. GPL is very intrusive license: if you use anything licensed under GPL, your whole project is automatically GPL too. Period.

I have no idea who is lying. But someone on the RaceFlight side is lying. Why? If you do not know why it's because of money. An old universal truth. And I suspect this whole thing might have legal repercussions and someone will meet someone in a court. Is that good? No idea. Bottom line is: RaceFlight One is violating GPL license of a code it was based on.

Ah, there is one more small thing. According to some RF/BF devs and users, Preston Garrison always stated that RF One is not using Kalman filtering. More, users were apparently banned from Slack for suggesting RF One was using Kalman filtering. Guess what… The published code suggests RaceFlight One is using Kalman filtering… Funny….

I will try to keep my eye on it and if I will keep you posted in case of any major developments (if any)…

Update #1

No, there is no Kalman filtering in RaceFlight One after all. All occurrences of Kalman filtering are commented out

Update #2

After all, there is a Kalman filter in RaceFlight One. The commented out code refers to multi-state Kalman filter. Method PafUpdate that is used for gyro filtering is 1-state Kalman filter. Thanks DigitalEntity for discovery

Follow up for 2017.12.07

Leave a Reply

Your email address will not be published.