So I've seen similar claims to this a few times before since the advent of ADS-B receivers like the FlightAware feeders people are setting up now. Was not able to find anything that actually integrated into an app to use while flying.
Well, I put the receiver setup together with $113.90 in hardware (primarily Raspberry Pi + RTL-SDR). Project "Stratux" has begun.
Instructions on how to set up the Pi are below. This is a screen recording of me taking off and picking up ADS-B towers. I start getting signal at about 300' AGL, and good steady signal from 4+ towers at 1,500'. FIS-B weather on ForeFlight is working great.
This is only ADS-B (978MHz) "In", but it's still very useful -- in the broadcasts I'm seeing there is plenty of weather (FIS-B) information. I'd like to work on an ADS-B transmitter, but that will come later.
Here's what the receiver looks like:
http://i.imgur.com/ojTrmjE.jpg -- just velcro'd them together to carry around while testing.
http://i.imgur.com/dSL0zKF.jpg -- mounted in the plane.
Demo:
https://youtu.be/ahXVPsnjkq4
http://i.imgur.com/1vFqkZP.jpg
http://i.imgur.com/8TqR1cB.png
I charge this power bank up, attach it to the velcro strips stuck in the baggage area of my plane, and fire it up. It creates a WiFi network just like Stratus and starts sending UAT information as it is received. The power bank gives about 10 hours of runtime with the Pi.
If you want to make your own, here's the complete shopping list:
http://amzn.com/B00MV6TAJI $69.99
http://amzn.com/B00P2UOU72 $25.95
http://amzn.com/B00JM59JPG $13.99
http://amzn.com/B000TGSPV6 $3.97
Below are is a rough overview to get it up and running. If there is enough interest, in a week or so there should be a packaged version of this available for easy setup.
1. Install Raspbian.
2. Install Go, RTL-SDR software/tools/drivers, C compiler, hostapd, isc-dhcp-server.
3. Set up hostapd and isc-dhcp-server so that the Pi creates a wireless network on network 192.168.10.0/24 and assigns IPs via DHCP on this subnet.
4. Get dump978 and compile.
5. Get stratux and compile gen_gdl90.
6. rtl_sdr -f 978000000 -s 2083334 -g 48 - | dump978 | gen_gdl90
7. Connect to the WiFi network in ForeFlight and look in the "More" tab and then under "Devices". You should see "FreeFlight". You're now ready to try it out. Enabling "Show ADSB Towers" is useful so you can see the tower information and such.
8. Enjoy. Follow the same steps as Stratus etc. Enable Traffic, Radar, etc. in your ForeFlight display.
That's "it". Again, if there's enough interest then I'll package this all up nicely so that it's just a couple steps.
In the process of getting this working, I wrote some code also to send 1090ES traffic data directly to ForeFlight (instead of relying on TIS-B re-broadcasts). Some work will be done to combine this with the UAT receiver, but that will come with time. Here's what it looks like:
Demo:
https://youtu.be/w_rfNQl-se8
Future plans:
1. TIS-B traffic needs to be tested. FIS-B weather is working great.
2. Implement "Stratux Replay" - "When the screen is turned on again, Stratux automatically sends ForeFlight Mobile any ADS-B weather that was missed, including radar, METARs, TAFs and PIREPs."
3. Figure out some dual-band setup for 978MHz + 1090MHz that is clean. You can get it going with a second RTL-SDR, but that'd be two dongles and two antennas -- not ideal.
4. ADS-B transeiver (transmit). There are some $30 WAAS USB GPSs on Amazon that would be great to test out, maybe someone has tried one and has some feedback.
