DIY ADS-B?

CoffeeIcePapers

CoffeeIcePapers

Well-Hung Member
Can anyone point me in the right direction, or is this even possible? I am mainly interested in building something that would allow me to get ADS-B weather and broadcast it via BT, but not pay $700.
 
mojo6911 said:
Can anyone point me in the right direction, or is this even possible? I am mainly interested in building something that would allow me to get ADS-B weather and broadcast it via BT, but not pay $700.
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Let me know if you come up with something...I've been looking on and off for a while, but nothing. Honestly I'm amazed there aren't a bunch of manufacturers fighting for the market for a cheap ADS-B weather BT receiver (screw ADS-B traffic, I just want weather).
 
I bought an RTL-SDR USB dongle a while back and love it:
http://www.amazon.com/NooElec-RTL-SDR-RTL2832U-Software-Packages/dp/B008S7AVTC

Not a bad deal for $19.95, considering it works as a wideband radio scanner and a pretty damn good spectrum analyzer (with a program called SDR#).

I followed this tutorial on setting up Virtual Radar Server, which is free: http://www.rtl-sdr.com/adsb-aircraft-radar-with-rtl-sdr/

I didn't build the J-Pole antenna, since the stock one works fine. As far as ADS-B weather, I'm not sure if anyone has tried to venture into decoding that yet (everything I've seen focuses on traffic). Most of the software I've seen focuses on decoding ADS-B from the aircraft to the ground station. I'm not sure anyone has successfully decoded the FIS-B (weather) or TIS-B (traffic) uplinks from the ground station. If you think about it there would be limited demand from a hobbyist standpoint, since it would only apply to the few people who live close enough to have line of sight with one of the ground stations.

The RTL-1090 program in the tutorial decodes the raw ADS-B data bits though, so you could probably extract them from there? I hope this is a good start at least.

More tutorials:
http://www.hamradioscience.com/the-rtl-2832u-sdr-and-ads-b/
http://planefinder.net/about/ads-b-how-planefinder-works/

You can also put it on a Rasberry Pi and make it REALLY portable:
http://www.rtl-sdr.com/virtual-radar-server-running-on-a-raspberry-pi-with-mono/

FWIW the RTL-SDR also decodes ACARS. ;)
 
ComplexHiAv8r said:
@drunkenbeagle have you looked into anything along these lines?
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Yeah, I have. Realized that it was enough work that I would not bother building and debugging something like that for fun.

A VOR, DME or GPS receiver is simple enough to design and build yourself. ADS-B, not so much. Mostly, as has been pointed out, there are a lot of protocols to understand/reverse engineer.
 
drunkenbeagle said:
Yeah, I have. Realized that it was enough work that I would not bother building and debugging something like that for fun.

A VOR, DME or GPS receiver is simple enough to design and build yourself. ADS-B, not so much. Mostly, as has been pointed out, there are a lot of protocols to understand/reverse engineer.
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I thought of you as soon as I saw Rasberry PI 8)

Shouldn't you be drinking???
 
Are you trying to feed data to a third-party program like Foreflight?

I didn't do a ton of reading on it but it appears FIS-B is on a separate band called UAT. Everything that people appear to be building to this point is 1090ES which seems to be reserved to the big boys (jets) and doesn't include FIS-B. There is an FAA document describing UAT located here... http://adsb.tc.faa.gov/WG5_Meetings/Meeting1/UAT-WP-1-09.pdf

Once you get the data though I'm not sure what you're going to do with it unless you build up your own GUI. My few quick searches about Foreflight and Garmin indicate that they're not leaking the secret sauce to how they're getting the data over Bluetooth. Protocols can be reverse engineered but dang that would be a TON of work.

If I ever get this Raspberry Pi working in my car with Bluetooth maybe I can shift some focus to this project. At least get the SDR to pull in the data. Maybe Foreflight will eventually put up an SDK for their Bluetooth stuff.
 
bronco21016 said:
Are you trying to feed data to a third-party program like Foreflight?

I didn't do a ton of reading on it but it appears FIS-B is on a separate band called UAT. Everything that people appear to be building to this point is 1090ES which seems to be reserved to the big boys (jets) and doesn't include FIS-B. There is an FAA document describing UAT located here... http://adsb.tc.faa.gov/WG5_Meetings/Meeting1/UAT-WP-1-09.pdf

Once you get the data though I'm not sure what you're going to do with it unless you build up your own GUI. My few quick searches about Foreflight and Garmin indicate that they're not leaking the secret sauce to how they're getting the data over Bluetooth. Protocols can be reverse engineered but dang that would be a TON of work.

If I ever get this Raspberry Pi working in my car with Bluetooth maybe I can shift some focus to this project. At least get the SDR to pull in the data. Maybe Foreflight will eventually put up an SDK for their Bluetooth stuff.
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Open up their device, figure out the traces that go to the bluetooth module, attach a logic analyzer... shouldnt be too hard to figure out.

Building an RF device that works on two bands would be a lot of worh though, I doubt the SDR hacks would be reliable enough to use
 
I saw a guy somewhere using a more advanced (read: expensive) that was monitoring multiple police channels using SDR. Not real sure how it was all working. I'm sure I could find it with some Googling.

As far as the protocol goes I was thinking use Bluetooth sniffing software and you might be able to figure it out. I'm not sure if they're doing some sort of encryption on it or not. I know some of the modules also work through wifi so that could be a way of sniffing the traffic.

I don't fly GA pretty much at all anymore so Foreflight etc wouldn't do much for me. Graphic weather depiction would though. Here's my idea.... Build a FIS-B receiver using RTL-SDR and a Raspberry Pi. On the Pi add a wifi module and serve up a web page that displays the weather information. No need for multiple apps to develop that way including Apples ridiculous restrictions. While you're at it you might as well serve up a directory of plates as well. Would definitely be nice to have the whole radar picture on board some days.
 
Capt. Chaos said:
The FIB-B out on the 890hz UAT frequency requires a UAT equipped aircraft to be broadcasting to the ground station before it broadcasts any FIS-B data.
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TwoTwoLeft said:
https://www.reddit.com/r/flying/comments/3fscia/the_11390_adsb_receiver_for_foreflight_or_pretty/
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These two things seem to contradict each other. According to the redditor he was receiving FIS-B. Is it possible it's being broadcast because some other UAT equipped aircraft in the area is requesting it?

Either way kudos to whomever figured out how to feed data to this software! This setup would be so amazing to have in a jet. Live radar coupled with a national radar loop for the big picture!
 
killbilly said:
I suspect your time - at the end of the project - is worth the $700 it would take to buy an ADS-B unit.
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I got my stuff shipped to the FBO and I'll be putting it together in my hotel room while I'm out for work. I'd have to skip a meal or two to make my per diem pay for a Stratus....
 
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