My Attempt at a $115 ADS-B Receiver Build for Foreflight

JoseCuervo

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JoseCuervo
(Disclaimer: A user on Reddit has written the software and sourced the components to build a "Stratus" type of clone/device/knockoff that can be built for less than $115. This thread attempts to chronicle my attempt to use his information to actually build the device. I take NO credit for the greatness of his work, nor do I have the technical knowledge to explain much of what I am doing. Please go visit the Reddit threads (linked below) to see the evolution of what he built. This thread just is my journey in following his instructions.)











I stumbled across a reference to Reddit thread where they were discussing the ADS-B In device that could be built for $113.90 according to the OP, "strangerwithadvice". For a fun, and hopefully useful project, I was intrigued.







Original Thread: The $113.90 ADS-B receiver for ForeFlight (or pretty much any other EFB)







Second Thread that is more the Assembly process:



$113.90 Thread, Part 2











Bit of Background: A long time ago, I used to be comfortable swapping PC cards in and out of boxes, and loading software, but, it seems that everything is a closed box these days, so that doesn't even happen. I am not a Linux expert, a Tech Geek, or anything close. But, I am a pilot, and, like most pilots, I am a bit cheap, uh.... thrifty, so the chance to get ADS-B In for $113.90 was worth the risk.











Step 1: Order the parts from Amazon.



As, I was trying to follow his directions to a "T", I ordered everything he linked. I did not try to shop around for other pricing, I didn't try and find substitutes, I wanted what he advised.











The items you are order are:



  • A small computer called a Raspberry Pi


  • A Battery power source that will provide 10 hours life


  • An RTL-SDR & ADS-B Reciever Set


  • And some Velcro





The Reddit user says they are $113.90, when I loaded them in my Cart at Amazon, it came up to $115. I don't know why, I don't care why. With Amazon Prime, I bought them Friday, they were in my office on Monday. Good enough.



0596a1df633a177aacf8f516959598dd.jpg








(Battery pack that should provide 10 hours of life. Also could power the iPad, perhaps??)

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What is a Raspberry Pi??? Good question. Up until Friday, I had never heard of one. Turns out they are a "computer" that are dirt cheap and can be used for some very specific tasks. Go learn about them, the applications are amazing. The one I got for $70 can also be configured to be a complete media Center for your home entertainment system. It looks like there is a whole user group out there building some cool applications using this $70 computer. I will do another project with it.







The Raspberry Pi kit comes with an acrylic case, a power cord, an 8gb memory card, a WiFi antenna/card, plus 4 USB ports, an ethernet port, and a bunch of other features for media.







Step 2: Physical Assembly of Raspberry Pi was easy, put the card in the case, snap the lid on, and you have a computer.



743fb7ce98c236baa1d421c1304b3829.jpg




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Operating System for Raspberry Pi: These little computers use a form of Linux called Raspbian. The memory card with the computer had a version of Raspbian pre-loaded, but the Reddit user had created another version that had Raspbian PLUS his ADS-B software. This made for the biggest task, writing the software onto the memory card.







Step 3-10: My steps, as best it worked were:



  • Download the ZIP file of his Raspbian+ADS-B


  • Download a card writing utility called win32imagewriter


  • Install the image writer software on my desktop


  • Extract the Raspbian+ADS-B software


  • Using the image writer software, write the Raspbian+ADS-B image/operating system onto the memory card


  • Install the Memory Card in the little Raspberry Pi computer


  • Install the WiFi /USB network card/chip


  • Power up the Raspberry Pi









At this point, as you don't have a display (you could hook one up to the Raspberry Pi, but I did not bother) you should have a functioning computer and WiFi network.







I hooked up the RTL-SDR & ADS-B "stick" into an available USB port. This device is a Radio Tuner that probably can do way more than I understand. I have a hunch the "ADS-B" portion is all I am going to use. Some of the Radio guys might understand more what comes $22 device (with a remote control!!).







I powered it up, lights blinked!!!











Testing:



Then, to see if the network was there, I used my iPhone to search for wireless networks and found a new network called "Stratux". I had successfully configured the Raspberry Pi to run his Raspbian OS and ADS-B software.



fa19a21f9563e1a82ccb9b6e39f9bda7.jpg
















I then opened up ForeFlight and went to the Devices section and selected "FreeFlight" in the devices section.



5722dabbeaff5c0754af79c83105c267.jpg
















Then, going to the Maps in ForeFlight, I was able to see that "FreeFlight" was working with "0 towers". I am told that on the ground, it is not unusual to not see any towers.



be8be2ad0769db2260e4d603bce7104b.jpg










Next step: I think the Velcro is there for a reason. I will velcro the battery pack, when it gets done charging, to the Raspberry Pi, twist tie the cords nicely, and then go figure out where to mount it in the plane and take it for a test run with my iPad.


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With this device, there are no longer any barriers to the average pilot, owner or renter, to NOT have ADS-B weather (and perhaps traffic).
 
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There is a similar thread going on the DFWpilots board.

I'm curious as to your results when you get out there and flying. Keep us posted!
 
Yes, I am also curious to see your results.
I have been using the $20 ADSB receiver for almost 2 years now at home, and it works great for traffic only. It would be nice to see the weather/notams side working too on the same general setup (though I realize I'll never see that from ground level).
 
The iPad can now find the Stratux and FreeFlight ......


69d12fce6238fae38cd733683b44d6d0.jpg



d1b9369b2630dc57869c8709b55ac90c.jpg
 
I also just put one of these together last night! (exact same reddit thread, instructions, parts, and results).

However, I had help. My 8 year old daughter did most of the work :D. Yes, everybody, it was really that easy.

Haven't flight tested it myself but plan to tomorrow, hopefully.

I saved some money since I already had the velcro... ;)
 
Congrats on your technological progress. It's not that hard of a job. I would like to know the real world benefit for Joe Bagodonuts out flying his SpamCan 9000 around Anytown USA.
 
It's mostly a toy until that one day when you really need it, like last time I was transitioning Class C of Colorado Springs under ATC vectoring and with no warning the controller said "831RC descend to 6000 NOW". I cut the throttle and pushed over a little bit and in 3 seconds a C210 flew right over so close that I could almost see rivets. His approach from my right was completely obscured by the airframe.
 
Congrats on your technological progress. It's not that hard of a job. I would like to know the real world benefit for Joe Bagodonuts out flying his SpamCan 9000 around Anytown USA.


I would think the benefit would be the access to Radar in flight (I make 400 mile cross countries, from Sea Level up to and over 10k mountains, high deserts, and lower valleys), TFR's this time of year are popping up daily for fire fighting reasons (and camping in the back country on grass strips along rivers without Cellular and Wifi prevents weather data on the way home).

Certainly worth the risk of $115 and an hour and a half of putzing around on the computer compared to Sporty's $600 Stratus1..
 
I also just put one of these together last night! (exact same reddit thread, instructions, parts, and results).

However, I had help. My 8 year old daughter did most of the work :D. Yes, everybody, it was really that easy.

Haven't flight tested it myself but plan to tomorrow, hopefully.

I saved some money since I already had the velcro... ;)


Post your results, and what you did with the antenna to get best reception. That is the next trick.
 
I'm hoping to see access to weather radar, and maybe some traffic info, and also the real time listing of TFRs as they generate across the western US. Let us know when you get any of this stuff up.
 
Very interested, but I want a flight report that this works from someone here before I go shopping on Amazon. :)

I wonder what the Foreflight/Appareo folks think of this? They can't be that happy if it ends up taking off. I could see Foreflight trying to block this somehow in a future update...
 
Just read the Reddit comments. Plenty of pilots w/ screenshots (on the ground and in flight) of it working in multiple apps that work with the Stratus.
 
Is it 978 only?


Sent from my iPhone using Tapatalk
 
Well, I don't know where FIS-B stations are located, and if they aren't where I am going, having the best or even the cheapest in solution isn't helping much. I fly mostly in remote areas. Including a lot of mountain flights. So, I'll think about getting one of these up and running then take a cruise out in NM/CO area and see what I get. Guessing it won't be much, but hope to be pleasantly surprised.
 
Well, I don't know where FIS-B stations are located, and if they aren't where I am going, having the best or even the cheapest in solution isn't helping much. I fly mostly in remote areas. Including a lot of mountain flights. So, I'll think about getting one of these up and running then take a cruise out in NM/CO area and see what I get. Guessing it won't be much, but hope to be pleasantly surprised.


I saw a map of towers.... there are gaps in the west. No surprises there, as there aren't people in some of those places...


Edit: This might be the coverage.... or not...
ADSB-final.png


Colorado looks pretty covered.....

stratus-coverage.png
 
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If anyone has any questions, I set this exact system up a week ago. Works like a champ. I'm fortunate the adsb tower is about 50' from my hangar door so I'm always guaranteed one tower. At 1000' I have three towers locked, one about 50nm away with the antenna velcrod to the window. I've seen plenty of weather but no traffic yet, but then the two flights I've done it's been very dead out. I skipped the battery the last flight and ran it direct off my usb cigarette adapter.
 
Okay, I got this all configured and up and running...

iPhone sees/connects the "stratux" network
ForeFlight sees/connects the "FreeFlight" device
However I'm not seeing the "FreeFlight, 0 towers" message, like in the attached image, when I open the Maps in ForeFlight. Is this an issue?
be8be2ad0769db2260e4d603bce7104b.jpg
 
I've flown with the device using with the following iOS apps on the iPad:

  • ForeFlight works no special config
  • WingX works no special config
  • FltPlan Go does not work on the iOS version ... data is collected from the ADS-B towers but it does not flow into the application (ie Metar, TAF, winds, etc. remain stale). I've been exchanging emails with FltPlan support. The "Stratux" does work with their Android version but requires you open custom port 4000 in a helper app.
  • FltPlan Go (iOS) Update It works! You need to turn off the "Metar Layers" on the map page (think of that as "internet weather") and use the options under ADS-B. Choose Clarity as the device.
  • FlyQ works but requires a customized SSID to be recognized by the application.
  • FlyQ Update FlyQ is not working. It briefly recognizes the device but then disconnects after +- 30 seconds ... then tries to reconnect, and repeats. A number of us have corresponded with Seattle Avionics and trying to get a solution.
Some observations after making a number of flights with the device:
  • Antenna First time I flew I placed the antenna on the glare-shield but that meant the rest of the "device" is very close to the panel ... and it created interference with my transponder. The IDENT light would flash as if it was being interrogated in sync with the ADS-B "heartbeat." So I ended up moving it to the back seat / baggage area and placed the antenna in the window. This is one reason for purchasing the battery pack - it allows lots of flexibility for placement in the plane. And bring some velcro!
  • Antenna Length If you have an antenna that extends, keep it short! Lots of folks are reporting shorter antenna's do a much better job picking up the ADS-B data. The optimum antenna length was between 5.5 and 6.5 inches, which corresponds to the calculated 5.75 inches at 1/2 wavelength for a 978MHz frequency. That has been my experience as well in the plane after trying various extensions ... I picked up many more towers.
  • USB Dongle gets very (very) warm to the touch! Lots of comments about this on various forums but manufacturer has assured everyone this is normal and nothing to be concerned about. But you do want the device placed where it gets air circulation.
  • GPS A reminder this device (in its current incarnation) does not have a built in GPS so your tablet either needs a built in GPS or you can connect to an external GPS via bluetooth (as the Stratux will be using your WiFi connection).
  • On the ground don't expect to pick up any info unless you are at an airport that has an ADS-B tower.
  • Lots of new builds can be found here: https://www.reddit.com/r/stratux
 

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I've flown with the device using with the following iOS apps on the iPad:

  • ForeFlight works no special config
  • WingX works no special config
  • FltPlan Go does not work on the iOS version ... data is collected from the ADS-B towers but it does not flow into the application (ie Metar, TAF, winds, etc. remain stale). I've been exchanging emails with FltPlan support. The "Stratux" does work with their Android version but requires you open custom port 4000 in a helper app.
  • FlyQ works but requires a customized SSID to be recognized by the application
Some observations after making a number of flights with the device:
  • Antenna First time I flew I placed the antenna on the glare-shield but that meant the rest of the "device" is very close to the panel ... and it created interference with my transponder. The IDENT light would flash as if it was being interrogated in sync with the ADS-B "heartbeat." So I ended up moving it to the back seat / baggage area and placed the antenna in the window. This is one reason for purchasing the battery pack - it allows lots of flexibility for placement in the plane. And bring some velcro!
  • Antenna Length If you have an antenna that extends, keep it short! Lots of folks are reporting shorter antenna's do a much better job picking up the ADS-B data. The optimum antenna length was between 5.5 and 6.5 inches, which corresponds to the calculated 5.75 inches at 1/2 wavelength for a 978MHz frequency. That has been my experience as well in the plane after trying various extensions ... I picked up many more towers.
  • USB Dongle gets very (very) warm to the touch! Lots of comments about this on various forums but manufacturer has assured everyone this is normal and nothing to be concerned about. But you do want the device placed where it gets air circulation.
  • GPS A reminder this device (in its current incarnation) does not have a built in GPS so your tablet either needs a built in GPS or you can connect to an external GPS via bluetooth (as the Stratux will be using your WiFi connection).
  • On the ground don't expect to pick up any info unless you are at an airport that has an ADS-B tower.
  • Lots of new builds can be found here: https://www.reddit.com/r/stratux

From what I read, it seems to me that in all the above configurations, receiving weather and traffic on 1090 MHz would require having two separate dongles. This means that for the normal single-dongle device, assuming FIS-B weather is required, only a small fraction of the IN-only traffic will be depicted.
And of course IN-only traffic is a small fraction of the traffic available to OUT installations. (And even the latter only show traffic which ATC is showing.)
So anyone considering this solution should be aware that even on paper its traffic capabilities are significantly reduced compared to off-the-shelf products like Stratus and GDL-39, which are notoriously limited without OUT installed.
(I am assuming that anyone with an installed OUT would also have a dual channel IN.)
I stand to be corrected, however.
 
You are absolutely correct ... and guys have already tested the unit using (2) antenna dongles ... one on the 978 band and the other on 1090 with success. FIS-B Weather only comes in on 978 so that works as designed ... the extra 1090 antenna would help with high up traffic ... but like you, I would not count on the reliability of the displayed traffic unless you were equipped with ADS-B Out.
 
Interesting article about TIS-B on 978mhz that I found on the stratux subreddit:

http://www.faa.gov/nextgen/programs...ce_change_summary_final_508_5-13-15-webv2.pdf

Summary as I understand it- late in 2015 the FAA will begin transmitting all traffic on 978 even if you don't have ADS-B out as long as you are in Fan area of FAA radar coverage and WAM.


Sent from my iPhone with Tapatalk

I hope you are correct, but the way I read it is that you'll only get TIS-B traffic broadcast (i.e. your own "traffic puck") if you have certified ADS-B out. In the past if the OUT was uncertified it would not show up on the ADS-B In broadcasts, whereas starting late 2015 all OUT emitters will be shown, regardless of certification status. However, I think the uncertified OUT aircraft will no longer receive a broadcast at that point.
I am not 100% sure about this, and will be happy to be proven wrong, since all I have is a passive IN at the moment.
 
Interesting article about TIS-B on 978mhz that I found on the stratux subreddit:

http://www.faa.gov/nextgen/programs...ce_change_summary_final_508_5-13-15-webv2.pdf

Summary as I understand it- late in 2015 the FAA will begin transmitting all traffic on 978 even if you don't have ADS-B out as long as you are in Fan area of FAA radar coverage and WAM.


Sent from my iPhone with Tapatalk

Your summary is a complete misreading of the referenced FAA document. Here is a summary that is close to what the FAA found and what they plan to do.

The FAA found bogus ADS-B Out systems that were gumming up the system and making aircraft using this bogus equipment invisible to certified aircraft systems. They intend to cut those bogus systems off by no longer treating them as clients and no longer waking up the ground station around said bogus systems. When such a bogus system is detected around a compliant ADS-B Out system, a TISB will be generated for the bogus system target so that it will not be invisible.

I have heard anecdotal information that owners of the bogus systems have been getting letters from the FAA to cease and desist or they will arrange a visit to the local FSDO.

As far as portable receivers go, there are no restrictions or any planned in the future. This only applies to systems that are broadcasting. My understanding is there are about 2300 systems currently detected as broadcasting the bogus information and many are portables.
 
Your summary is a complete misreading of the referenced FAA document. Here is a summary that is close to what the FAA found and what they plan to do.

The FAA found bogus ADS-B Out systems that were gumming up the system and making aircraft using this bogus equipment invisible to certified aircraft systems. They intend to cut those bogus systems off by no longer treating them as clients and no longer waking up the ground station around said bogus systems. When such a bogus system is detected around a compliant ADS-B Out system, a TISB will be generated for the bogus system target so that it will not be invisible.

I have heard anecdotal information that owners of the bogus systems have been getting letters from the FAA to cease and desist or they will arrange a visit to the local FSDO.

As far as portable receivers go, there are no restrictions or any planned in the future. This only applies to systems that are broadcasting. My understanding is there are about 2300 systems currently detected as broadcasting the bogus information and many are portables.


Can you explain what "bogus" means? Are these the same as "non-certified", or is this some sort of malicious act of actual "false" information?
 
From the FAA memo, linked above....

The results of these changes will be:
(1) All ADS-B-In systems will see other aircraft equipped with ADS-B Out and transponders in areas with FAA radar/WAM coverage (complete & accurate traffic picture)
(2) Compared to the current state, aeronautical protected spectrum will be more efficiently used
(3) FAA will eliminate the current incentive for operators to equip with ADS-B Out systems that are not compatible with certified ADS-B-In systems
 
From the FAA memo, linked above....

What John said above is the way I read the document too, but was hoping to be proven wrong.

As I understand it, when the FAA say "All ADS-B-In systems will see other aircraft", they mean All Certified ADS-B-In systems, which include a certified OUT component. For the FAA the ubiquitous portable IN-only systems are apparently irrelevant/invisible. I guess another way of interpreting it is that non-OUT (passive IN) systems will also see other aircraft, but only inside "pucks" intended for any OUT aircraft in their area.
 
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Can you explain what "bogus" means? Are these the same as "non-certified", or is this some sort of malicious act of actual "false" information?

It is my shorthand for ADS-B Out systems that self identify that they are not to be trusted, for example SIL = 0 or SDA = 0 or NIC below a threshold. Portables are required to use SIL and SDA of 0. Some installed systems also broadcast these values, in most cases because they are not using a compliant position source or have not been configured properly. However, these systems indicate they are at the version of function RTCA DO-282B or DO 260B that is intended to meet the 2020 requirement.
 
From the FAA memo, linked above....

The results of these changes will be:
(1) All ADS-B-In systems will see other aircraft equipped with ADS-B Out and transponders in areas with FAA radar/WAM coverage (complete & accurate traffic picture)
(2) Compared to the current state, aeronautical protected spectrum will be more efficiently used
(3) FAA will eliminate the current incentive for operators to equip with ADS-B Out systems that are not compatible with certified ADS-B-In systems

The bold text is intended to respond to the fact that certified ADS-B in systems, those that comply with TSO C195a, for example the NavWorx 600B, the Flight Stream Ranger, the L3 Lynx, and the Garmin GDL88 or GDL84 are not permitted to display targets with the SIL=0 or SDA=0 (self declared as untrustworthy -my term bogus devices). Since certified systems can't display these targets, they are effectively invisible as it currently stands. Today these Bogus systems are treated like any other client by the ground stations and a TISB is not generated for the client own ship. By this change, a TISB will be generated for these clients, which has the effect of making them visible to the certified boxes. For non certified receivers, they will see multiple targets, one from the Bogus device, the other from the TISB for the same aircraft. By the beginning of next year, the major incentive of using these bogus devices will be removed, in that the ground stations will no longer afford them with client status.
 
I ordered the parts. It looks like a fun project. Mine total was $110. Strange how it varies so much.
 
I found something called a Rasberry Pi Starter Kit that has the WIFI, case and power cord but also has a cooling fan for the computer. At $25.73 for the kit and $35 for the R PI 2 I'll save even more dollars (only 60.73 vs 69.99) and get a better set up.
I plan on making the buy when I get home next week.
 
Question for current users...are you getting both traffic and wether on your tablets or just one or the other?
 
I found something called a Rasberry Pi Starter Kit that has the WIFI, case and power cord but also has a cooling fan for the computer. At $25.73 for the kit and $35 for the R PI 2 I'll save even more dollars (only 60.73 vs 69.99) and get a better set up.
I plan on making the buy when I get home next week.


Does it have the memory card?
 
I set this up I had all the stuff since I had a 1090 set up before. I am trying to use it with AVARE which supposedly works but all I get is a time and battery data. I don't know if I am not close enough to a tower to get data on the ground or if something else is wrong.
 
I set this up I had all the stuff since I had a 1090 set up before. I am trying to use it with AVARE which supposedly works but all I get is a time and battery data. I don't know if I am not close enough to a tower to get data on the ground or if something else is wrong.

Have you considered driving it to the nearest ground station?
Here are the current locations:
http://www.faa.gov/nextgen/programs/adsb/coverageMap/
You might be lucky with one not too far from home.
 
Well I did try driving to a high point nearby. Still same issue. I will try it in the plane at some point or try getting closer to a ground station.
 
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