
Raspberry Pi inspired autopilot - ivereninov
http://www.emlid.com/
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Alupis
For those looking at the pictures and thinking "that's not a Raspberry Pi!",
it is... under the black Navio+ board is a new Raspberry Pi model B+[1]

[1] [http://www.raspberrypi.org/products/model-b-
plus/](http://www.raspberrypi.org/products/model-b-plus/)

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gadders
When I read things like this, it always reminds me of the Kiwi chap that was
trying to build a cruise missile in his garage [1]. Although this is smaller
than what he had planned, I would imagine you could add a "release"
functionality to the Pi Autopilot so it could drop _something_ when at a
certain position.

[1]
[http://aardvark.co.nz/pjet/cruise.shtml](http://aardvark.co.nz/pjet/cruise.shtml)

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tomsunax
Bruce is very much into quadcopters and other hobby-rc stuff these days. Check
out his YouTube channels if you want to see more of him, quite informative

[https://www.youtube.com/user/RCModelReviews](https://www.youtube.com/user/RCModelReviews)
(educational)

[https://www.youtube.com/user/xjet](https://www.youtube.com/user/xjet) (fun
stuff)

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klinquist
Using the RPi as a video encoder may be the "killer app" for this. Currently,
there isn't a "ready to fly" solution that will encode video and send it out
over LTE.

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ivereninov
Exactly! We are working on this and will include a very easy to use LTE
streaming configuration for HD FPV experience.

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shoggs
Is it actually possible to fly FPV with that much of a delay?

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zo1
Why would there be large delay? Am I missing something that you'd care to fill
us in on?

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Phlarp
Most hobbyist multi-rotor flyers use an analog video feed over 1.2ghz or
5.8ghz radio, which has very minimal lag. Converting the video to a digital
signal typically introduces 500-1000ms of delay, which is enough to make
flying by the camera difficult or nearly impossible. Transmitting the signal
over an IP switched network would likely introduce more lag in addition to the
digital conversion.

Ultimately it will depend on which you value more-- response time or
resolution.

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mavkhimenia
The delay with Raspberry Pi camera module and proper LTE\WiFi link is much
less - it's around 100ms.

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lacksconfidence
Do you all have any plans to shave that further? What might be considered the
ideal maximum latency for things like flying obstacle courses(fpv racing)?
landing from fpv?

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tomswartz07
This is very neat!

Has there been any thought about using the 'Compute Model' RasPi? It's the
RasPi in the DIMM form factor. Perhaps this would help lighten up the payload
even more?

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mavkhimenia
Thanks! We've been thinking of it, but rejected the idea. RPi A+ is quite
light, so RPi+Navio weighs as the normal autopilot. Also, A+ is much cheaper.

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scoot
> _RPi A+ is quite light, so RPi+Navio weighs as the normal autopilot_

Not to detract from the novelty value of an RPi based flight controller, but
if you were involved in the design, you must know that's just not true:

RPi A+: 23g, Navio: 24g, Total: 47g

APM Mini: 7g

That's a significant difference in a situation where every gram counts towards
flight time.

The Navio also costs 6X an APM mini, and that's before you add the RPi and
power module, which brings it to 8X.

I get why someone might develop this as a hobby project, but I can't think why
anyone would buy one.

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mavkhimenia
Navio does NOT weight 24g. It's weight is around ~12g. RPi A+ with Navio =
23+10 = ~35g. Pixhawk weights 38g.

With Navio+RPi you get a lot of stuff compared to hardware like APMMini:
network connectivity (LTE, long-range WiFi), affordable 1080p camera module
with H.264 encoder for FPV, a lot of processing power for advanced flight
algorithms (as an example - a lot of new features of APM such as EKF are NOT
available on old APM platforms) and the overall hackability, which you don't
get with any microcontroller based autopilot.

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zo1
How much hacking and/or electronics knowledge is required to set this up and
get it running?

#Edit. Another question, will the Reach (when it comes out) integrate easily
with the boards coming out in Februaray, and be supported as part of Navio+?

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VereninovIgor
Not much. Write an SD card image, install APM, connect to Wi-Fi or Ethernet
and you are ready to go. After that it requires calibration and setup in APM
Planner like any other autopilot.

Reach will be a replacement of normal GPS for any autopilot. It will be
compatible with Navio+.

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Jeandon
Looks very nice. Is Linux actually real-time enough to run autopilot code?

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MegaDeKay
The second PDF in the link below compares the Raspberry Pi with the Beaglebone
Black for a next gen APM. The nod went the the Beaglebone because of more
GPIO, PWM support, and the two PRUs for realtime operation. The Pi B+ helps
the first point, but not the other two. There is also a really interesting
page in here on the latencies that are required.

BTW, this was written by Andrew Tridgell of Samba fame.

[http://diydrones.com/profiles/blogs/a-peek-into-the-
future-o...](http://diydrones.com/profiles/blogs/a-peek-into-the-future-of-
ardupilot)

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2bluesc
Thanks for this. Whenever I see people running around high fiving over the
Raspberry Pi, I start to formulate an argument how the BBB would almost always
be vastly superior for slightly more cost.

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mavkhimenia
There a lot of boards that outperform BBB 10-20-30x times. But both RPi and
BBB are more than enough to run an autopilot code. One of the great advantages
of RPi over BBB is 1080p camera module with hardware H264 encoder as well as
bigger community.

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mjs7231
Just curious here. The CC3D boards were also open source, hackable, and only
1/3 the price, and guessing, but looks about 1/5th the size. What makes using
better than all those downfalls?

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igorvereninov
This is completely different. Autopilot runs under Linux and that gives
incredible flexibility. You can send HD video over LTE, run scripts in flight.
SSH to drone in the air, how cool is that?

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Phlarp
How is running scripts (locally?) or SSHing into it over a serial modem any
different from the scripting functions or telemetry information available with
APM or GCS (CC3D) based systems?

What advantages would the raspi have in streaming HD video over LTE that
strapping last years android phone to the drone wouldn't give me?

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igorvereninov
It is very different.You have a full Linux environment with multiple
libraries. It is great for education research and development.

When LTE is not available you can use long range wifi.

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simpsond
I'm somewhat intrigued by the HAT spec and how the daughter card provides the
OS a device tree fragment. Can you comment on the pains/gains from conforming
to it?

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igorvereninov
Did not help us much(since we are working with spidev and i2cdev), but did not
cause much trouble either.

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NietTim
I have thought about doing this before, but figured this would be too heavy.
Guess I was wrong, very cool!

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nacnud
How do the power requirements for the autopilot compare to that of the rest of
the flight hardware?

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asynchronous13
miniscule. The electronics will consume a few watts, the main motors will
consume several hundred watts.

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bhhaskin
This is awesome! How much weight does it add compared to traditional
autopilots?

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igorvereninov
Thanks! Additional 23 grams for raspberry pi A+

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bhhaskin
Not bad at all considering all of the extra processing power.

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nakedrobot2
Is this only 8-bit? That is not really responsive enough.

Currently the best-in-class are naze32 with baseflight/cleanflight firmware
(stunt, mini copters) or APM / pixhawk (mapping, cinematography, GPS)

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igorvereninov
It runs on 32bit ARM at up to 1GHz with 512MB of RAM. Completely different
league.

