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Homemade avionics

Posted By:
Alexandre Ponourko
Homebuilder or Craftsman
11
Posts
4
#1 Posted: 8/2/2009 17:59:00

Schematics and inspirations.

 

S53MV homemade avionics. 

MIT Course 16.682 Prototyping Avionics 



Reggie Smalls
Homebuilder or Craftsman
126
Posts
49
#2 Posted: 8/3/2009 08:13:42

The first link is very interesting!  Schematics for a whole range of interesting homebuilt aircraft instruments.  Is this your own web page?  Whoever did this deserves some kudos!



Jon McDonald
Homebuilder or Craftsman
25
Posts
12
#3 Posted: 8/3/2009 14:41:56

That is awesome!  Those avionics look light as well.  I've been searching for something like this for a while. Thanks!

 

Jon



Jon McDonald Building Sonex #1287
Alexandre Ponourko
Homebuilder or Craftsman
11
Posts
4
#4 Posted: 8/3/2009 14:56:15

Dear Reggie,

 

That page is not my own. I am not connected with author of that site.

 

I am surfing in Internet and blogs for bright ideas.

 

Regards,

 

Alexander.

 

 

 



Tom Brusehaver
Homebuilder or Craftsman
3
Posts
0
#5 Posted: 6/25/2010 20:28:55

Has anyone thought about home building a UAT? I've been digging around, and it seems like it ought to be done for under $100 (BOM). Certification, and all would probably be a consideration, but assuming that the FAA is gonna force all US aircraft to have one, and foreign sales would be icing on that cake.

It is really a simple design, FM transmitter running about 1MB/s data rate. Many manufacturers will build chips in the 800-1000MHz range (IE Maxim MAX2365 transmitter). The last couple pages of this PPT (http://www.icao.int/anb/panels/acp/wg/M/Seminar/presentations/SP23_UAT%20Briefing%201111703_1USA.ppt) lays out the format of the message, both receive and transmit.

The one challenge might be to build a big enough linear amplifier. I think it only needs to get to 10W, which is a bit, but not out of line. 

 

My gut feel is with enough cooperation, we could get 'em built for under $200 including all certification costs.


 

 



Anthony Goetz
Homebuilder or Craftsman
32
Posts
5
#6 Posted: 6/25/2010 21:39:16

 I don't know about amateur built transmitters at that power output. I have a feeling both the FAA and FCC would have something to say about that. You mention getting it certified, and that can be a heck of a process. I'll defer to others with more knowledge of this feasibility.

On the other hand...

ADS-B *in* capability is very much within the grasp of the hobbyist. I've been looking at 1090ES recently as there seems to be a more active hobbyist community listening in on those transmissions. The basics of it are a low noise amplifier, 1-2 filters (1090 MHz SAW filters are available from several places), and most often a logarithmic amplifier as an amp/detector. The output can be sampled with an analog-to-digital converter or a comparator driving logic level inputs into a microcontroller which then does the very simple decoding. I assume a 978 MHz (UAT) receiver would be more or less the same. From there, it can be as easy as plugging it into a laptop for display.


Some websites of interest:

http://www.lll.lu/~edward/edward/adsb/Very%20Simple%20ADSB%20receiver.html

http://miniadsb.web99.de/    (these guys sell a kit of a complete RF front end for 1090ES reception)

http://rxcontrol.free.fr/PicADSB/index.html

http://www.qsl.net/dl4mea/picadsb/picadsb.htm

And finally, the holy grail for information about both UAT and 1090ES, hidden under the guise of boring, bureaucratic technical meetings. See working group 3 and 5 and click their most recent meetings. Draft versions of DO-260B (1090ES ADS-B standard) and DO-282B (UAT standard) are available. They are the most recent draft versions, but I can't imagine much of the technical information changed before publication. For what it's worth, these documents go for $500-$700.

http://adsb.tc.faa.gov/ADS-B.htm


-Tony



Tom Brusehaver
Homebuilder or Craftsman
3
Posts
0
#7 Posted: 6/25/2010 22:10:17

Good info, thanks.

I know the FAA will get excited about homebuilt stuff on 978MHz, it might have to be a formal project, with some investment. Like I say, with maybe 20-50K airplanes needing these things, it might not be too hard to come up with the $$ to make it happen. Garmin charging $7-9K for one is so far out of line.

1090ES is non-started for most of GA (except jets) since it requires flying above 18,000ft.

The UAT is what we need.

I found the ICAO document 9861-AN/460 which lay out the message formats, and discussions about UAT transeiver design antennas, error recovery, and other considerations.

 

http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.118.6485&rep=rep1&type=pdf 

Just joining the RTCA as an individual costs about $600, and you get the documents for free (soft copy).