I recently happened to do a bit of research about other options besides Navio for the Raspberries and found two interesting alternatives:
The first one is incredibly cheap and seems to be a valid DIY replacement for Navio while the Erle-Brain 2 seems to be a more finished product. Anyone got some experience with them and willing to share it?
James,
Since this is Navio+ community forum I don’t think that I need any disclaimers that my point of view is biased 
Raspilot is an interesting project and very cheap too! It does not include NEO-M8N GPS, which will cost you extra and will also occupy the only available serial port on Raspberry Pi (Navio+ exposes serial port for radios or any custom need). They also claim that they have CAN and two UART, but these interface are actually routed to the MCU and tunneling them to the Raspberry Pi with good performance can be a very tough challenge. I believe that I have counted about 10 devices on a single SPI bus! Considering that real-time constraints have to be met, and switching between devices takes time I really wish them well in achieving stable performance. Only 8 PWM channels by the way.
Erle-Brain 2 Is basically the same as Navio+ minus the GPS. All sensors and chips are exactly the same, they have placed connectors a little bit different though. I believe that you can probably run Navio+ version of APM with it. You will get a 3D printed case, but I do not think that this how you actually measure that a product is polished. They offer it for 199EUR(220USD), this includes the Raspberry Pi (35USD). This brings us to 185USD for a board without GPS. And do not forget that if you connect an external GPS, you do not have a UART any more!
Navio+ has the widest spread, longest history and the best community with many successful projects!
Buying from Emlid you support development of real-time Linux images (our image is used by Raspilot), and APM on Linux. We have a team that got your back in case you have any troubles. Availability of our hardware is high and software only gets better.
If someone actually had any experience with these platforms feel free to post here.
Hi Igor,
Thanks for sharing your insight. Although biased, still useful to hear what you think.
This is interesting. Licensing-wise it’s going to be hard to validate anything that runs on top of Linux while it’s much easier to do so with a microcontroller device involved. Can you elaborate on this matter?
Interesting to hear that the boards have the same sensors!
The key point of Navio when compared to Erle-Brain 2 seems to be that it includes GPS onboard. But apparently you need an external antenna. Can anyone share good feedback on the Navio GPS? I’m not convinced about this reasoning since you guys launched Reach.
So my understanding is that since Navio will need an external antenna for the GPS (I’d love to get feedback on it being worthy), what i get from you is:
168 $/Navio + 35 $/Raspberry Pi = 203 $
which seems to be comparable with the 218 $ that Erle-Brain 2 costs and that already includes a case. @igor.vereninov is this correct? 15 $ is a reasonable quantity for a cage to me.
I might just buy the three of them and see which one outperforms which 
. I’d appreciate if more could share their opinion.
James,
I am not sure what you mean by licensing.
It not only includes same sensors, it actually copies Navio+. They even run Navio examples as “Erle-Brain2 tests”
External antenna gives you a great flexibility in antenna choice and leads to excellent performance. If you want to use Navio in a rover you can get a large rugged, weatherproof antenna or lightweight one for airborne application.
Reach also uses external antenna, for exact same reason. Actually it is a separate project, and has nothing to do with Navio+.
You will also need an external GPS, add 55$ to Erle-Brain 2 here. You will not have a port for radio when you plug in the external GPS.
The antenna/GPS reasoning seems to be clearly biased to your side but that’s fine, I quite like the reasoning you displayed here for having a GPS on mind.
This reasoning seems poor. While doing my research about autopilots what got my interest on Linux was this post https://3drobotics.com/the-tale-of-beaglepilot-a-linux-based-autopilot/ which seems to indicate that the Erle Robotics kicked off this work and from that, Navio jumped over. Wouldn’t this mean that you “copied” Erle Robotics?
James, my reasoning is purely from the engineering point of view, if you have any technical arguments to back your point I would be happy to address them.
Navio and first erle-brain appeared at approximately same time. We have focused on a Raspberry Pi solution, while Erle developed a BegleBone based one. We have since developed Navio+, a Raspberry Pi B+/B2 compatible version of Navio. When I was talking about copying I meant that their new ErleBrain2 dropped the BeagleBone platform and adopted every aspect of Navio+, all chips, pinouts, drivers and examples.
Ah! That sounds much more convincing thanks for walking me through it Igor.