scratch-built avionics

[SteveWrightNZ]

for those who are interested in constructing moving map displays, automatic position reporting systems, weather displays etc ;

http://www.xastir.org/

http://canardaviationwiki.dmt.net/wi...Built_Avionics


S

[karoliina]

I did some changes & additions to the scratch built avionics section in the wiki.

[SteveWrightNZ]

the APRS reporting system I think is amusing. It would be fun to install a traffic reporting system viz TCAS with a handful of off-the-shelf bits, for only a few hundred dollars.

[karoliina]

Hi,

If you want to join the project, you can do it here:
https://garage.maemo.org/projects/katix-efis/

You don't need to own Nokia 770 to get started, it runs on Scratchbox too on a Linux-PC.

Any kind of help is very much needed. If you think you can help, you can join the project from the abovementioned link. The license is GPL and you are free to use the source code in your own projects assuming their license is also GPL or a license compatible with GPL.

Best Wishes,
Karoliina

[SteveWrightNZ]

download from where ? I can only find a screenshot there.

[karoliina]

Quick step by step instructions how to make it work on scratchbox assuming that you have it already installed (read installation instructions from www.maemo.org).

Outside scratchbox:

You need to install some additional components:

In Ubuntu do the followings:

sudo apt-get update
sudo apt-get install subversion xserver-xephyr

cd /scratchbox/users/yourusername/home/yourusername/

Now checkout it from subversion version control system of garage.maemo.org
(you need to first create user account to garage.maemo.org, user it for username and password that are asked):

svn checkout https://garage.maemo.org/svn/katix-efis

Xephyr :2 -host-cursor -screen 800x480x16 -dpi 96 -ac &

And then in scratchbox:

Start scratchbox:

In Ubuntu:
cd /scratchbox
./login

In Suse:
cd /scratchbox
sudo sbin/sbox_ctl start
./login

then you are in the scratchbox that emulates the Nokia 770 environment:

cd katix-efis
dpkg-buildpackage -rfakeroot
cd ..
fakeroot dpkg -i katix-efis_0.1-4_armel.deb

export DISPLAY=:2

af-sb-init.sh start

from start menu you can now find the Katix-efis in the Extras-folder

To save you for the effort if you didn't want to go through all the steps above this time, I created a release of the armel binary. Should run with qemu target. It can be downloaded from here:
https://garage.maemo.org/frs/downloa....1-4_armel.deb
Source:
https://garage.maemo.org/frs/downloa...s_0.1-4.tar.gz

[SteveWrightNZ]

what a mission.. I will leave you coders to figure that out.

[karoliina]

It is not that hard that it looks. With following the instructions it is actually very easy.
Without instructions it would be hard.

But you can do so:
1. install Scratchbox with rootstrap from www.maemo.org
2. install the ready-made debian package to it with application manager

And you are done and ready to start the program.
Ok, installing the Xephyr and starting it you can't escape.

Or alternatively buy Nokia 770, download the package and open it with the application manager and you are done. With the actual device it is ridiculously easy, the hard route is only for developers.

[SteveWrightNZ]

I wonder how hard it would be, to build a microcontroller to interface to air pressure, gyros, etc etc, and then talk UDP to OpenGC. http://www.opengc.org


S

[karoliina]

Kate is doing it currently.

Her engine monitor works already (we get readings from sensors)

Calculating attitude and angle of attack is then a bit harder task.

But Kate is not using OpenGC because we want to use Nokia 770 as display because it is the cheapest way to do it.

[SteveWrightNZ]

excellant. We will use one of these AVR microcontrollers for machinery, so it might translate into aircraft use quite nicely.

http://www.jedmicro.com.au/avr200.htm

S

[SteveWrightNZ]

"Open Source Synthetic Vision with 3d airspace boundaries and signage"

version 0.3 Released 2006-11-20

http://www.cobbin.com/Open-Eagle.html Overview

http://www.cobbin.com/synthetic-vision.htm Home Page

edit:
"Side by side video of the Synthetic View along side the camera view - R/C model aircraft"
http://www.flightgear.org/~curt/UAV/...apt1-divx6.avi 52M Video


S

[karoliina]

Just to announce: we have been working with our EFIS project a bit further. It does not mean that it would work yet and there is no binary version released just yet, this is only in the subversion repository trunk, but now we have more or less a modular EFIS and engine monitor gauge drawing "library" which is easily configurable with configuration file to any kind of screen layout. Kate has also improved the mathematics behind the attitude, now it nearly works right. The EFIS also has now HSI and split view display configuration, so that it can display e.g. engine gauges or HSI on the other side of the screen.

We have been thinking how to improve the readability of the screen and we may end up doing some things differently from mainstream EFIS-style since there are several things that are slow and hard to read. Our friend is flying with Dynon D-180 currently and he is giving suggestions about how to not do certain things - he haven't used EFIS before, so he is an ideal usability test person for rethinking the concept.

I have some additional ideas how to develop the EFIS system further. I have had an idea about autopilot for some time now, and I think it could be doable at some point providing that the basic display functionality gets first right, that is already going to take a while still because there are no other active developers currently in our open source project than two of us.

However, I got a pretty cool idea: What came into my mind from autopilot one day was a such thing as fly-by-wire. What if the plane would have two sticks for pilot. One mechanical joystick as a backup for the event that the fly-by-wire would fail or malfunction. And then another joystick for giving controls to the computer. I was thinking that how flying could be simplified - the pilot wants to go to some direction and currently has to compensate gusts, wind etc. with the controls. How about if the fly-by-wire would keep the plane always 100% stable, pointing just to the direction the pilot wants. This could make especially the landing a lot easier - the computer would adjust throttle, rudders and stick to maintain glideslope, direction and speed accurately. I am not sure how it would work out, but I got the idea one day from cars. In my trip to Barcelona last summer I rented a tiny car, Chevrolet Matiz to drive around. I had already forgotten how hard car is to drive if you need to do everything by yourself, change gears, there was no traction and stability control system aiding the drive and no electrically enchanced wheel, no electric throttle pedal etc. but it was all mechanical. The difference to our Prius was enormous, Prius is so easy to drive, just driving with left hand with not much workload and this mechanically controlled car was requiring all control done manually. GA airplanes are nowadays like the mechanical cars, pilot adjusts everything and it requires lots of training to become a pilot and some people don't ever learn to even land a Cessna and I think that is why flying an aircraft is so unpopular nowadays and that is why they are all so expensive - because of the low volumes, the prices must be expensive. So what would be a breakthrough in my opinion, would be at least electrically enchanced controls but better, a total fly by wire. Why flying couldn't be as safe and easy as it is on the today's good cars and why fly-by-wire would be hard, complicated, expensive, and only for fighter jets. I think it don't need to be that hard and complicated - for example Moller is having trouble getting the fly-by-wire software right that has tens of millions of lines assember. But who says it needs to be assembler. And consequently where is then the need of having tens of millions of lines of code if one can do it for 10000 lines or maybe less with a higher level language. And I invented that, actually, I could do a fly-by-wire prototype and debug it safely with X-plane. So I would have joystick connected to fly-by-wire software which would then control X-plane rather than the joystick directly controlling the plane on the X-plane. Any comments/ideas/counter arguments?

[SteveWrightNZ]

Originally Posted by karoliina

What came into my mind from autopilot one day was a such thing as fly-by-wire.

It is easiest to select the autopilot and simply let go of the controls. The autopilot should accurately maintain the A/C in its' current turn, climb, or descent, and maybe migrate to the programmed profile. Either, simple up/down/left/right toggles or rotary controls select less or greater rate of climb/descent, or else the aircraft may be manipulated into its new disposition by the main controls and the autopilot system be recycled.

Originally Posted by karoliina

How about if the fly-by-wire would keep the plane always 100% stable [...] the computer would adjust throttle, rudders and stick to maintain glideslope, direction and speed accurately.

I would not trust the computer with the stick on short final. I would consider letting it have the pitch trim, but then the pitch trim is changing constantly as the airspeed comes back, so likely you would be thinking ahead the computer.

If the workload is high it is a relief to maintain a selected altitude, airspeed, or rate-of-something, so I might set up what I want to happen next.

I think cruise is where the AP belongs, managing my vertical and horizontal profile accurately, freeing me from mental calculation to whatever extent I choose.

Originally Posted by karoliina

So I would have joystick connected to fly-by-wire software which would then control X-plane rather than the joystick directly controlling the plane on the X-plane.

This is being done with FlightGear, where its UDP language is OpenSource so you can interface it to anything. And you get OpenEagle SV for free.

They make a FlightGear Plane like a UFO which has no actual flight characteristics, and then input data to it from electronic gyros and GPS, so it indicates the aircrafts real axes and heading in real time. Now the autopilot can be set to some setting and FlightGear will output to your aircraft real-life control system and follow your command.

Oh, did I mention that it comes with full Synthetic Vision.. nice.

S