Cheap EFIS finally coming.

Discussion in 'Instruments / Avionics / Electrical System' started by autoreply, Aug 27, 2013.

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  1. Jun 19, 2019 #41

    CharlieN

    CharlieN

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    The issue with the EFIS available on Droids at this time is they should not or can not be used as a primary display since the speed and altitude are derived from GPS, not from movement through the air.

    Blain, no schematic at this time. It would simply be based on the Stratux hardware, add pressure sensors and output to HDMI as a primary and since the code for outputting to Wi-Fi is there, that is usable too.
    The only mechanical work involved is the buffer/ controller for the sensors. I have worked with these plenty with Megasquirt engine controls but the Raspberry is new to me. I have assembled my Stratux which is as much as I know at this point.
     
  2. Jun 19, 2019 #42

    GeeZee

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    Seems like most of the EFIS cost is in the sunlight readable, high temp capable display. I found a professional grade tablet that claimed to be sunlight readable and capable of operating at elevated temperatures but it was $$$$ (almost as much as just buying an EFIS). The consumer grade tablets will overheat and shut down in a very short time if exposed to the sun. If you’ve found a $100 display that can come close to a Dynon or GRT (brightness/ operating temp) then you may have something.
     
  3. Jun 19, 2019 #43

    Vigilant1

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    FWIW, the old Nexus 5 version 2 was quite bright, it had a very good reputation for in-cockpit legibility. It was a lot brighter than more recent consumer tablets and phones. They can still be had cheaply, but I don't know if, from a supportability standpoint, they'd make a good display for someone wanting a long-term answer.
     
  4. Jun 20, 2019 #44

    spaschke

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    not if you have a tablet holder that cools the tablet. There are designs out there you can download and 3d print. There are also holders you can buy with fans that cool the tablet.
     
  5. Jun 20, 2019 #45

    N500BC

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    If outputting to HDMI with the pressure sensors to output baro altitude and airspeed why not connect to projector and project to a glass, having an HUD!! Now that would be quite cool.The HUD has been done. See this link:


    Mr. John Marzulli designed this. He uses a Raspberry Pi and a Hudly HDMIn projector and combiner glass.
    His code and all needed is on Github:
    https://github.com/JohnMarzulli/StratuxHud/tree/master/views

    So really all that is needed is to integrate the pressure sensors to the StratuX.
    All credit for this goes to Mr. John Marzulli.
     
  6. Jun 20, 2019 #46

    Hephaestus

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    Just keep in mind wifi and some aircraft equipment don't always play nice. My old radios were unintelligible if the phones wifi was on (and Android's sometimes just turn on automatically when GPS says near home or a used hotspot). It took a while to figure out that squawk. Whether that's a failing wiring, internal, antenna issue I don't know. I know it's not something I've read about before.
     
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  7. Jun 21, 2019 #47

    rv7charlie

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    I suspect that if you hook up a 'stock' Stratux to an HDMI display, you'll not see much. Since it can send WIFI data to many unrelated apps from unrelated companies, my assumption is that it's just supplying data, and the various apps are telling the tablet/EFIS/phone/etc what and how to display the data. Is anyone using a stock Stratux with a direct-connected display (not-phone/tablet/etc)?

    While some tablets can't handle the heat (Apple) and have a hard time being seen in sunlight (Apple), others seem to work quite well, and have displays easily readable in sunlight. My ancient Nexus 7, and the much brighter 2nd gen Nexus 7 both work just fine in an RV cockpit. Not many cockpits are sunnier than an RV-4's. Newer tablets are significantly better than my old ones.
    "The issue with the EFIS available on Droids at this time is they should not or can not be used as a primary display since the speed and altitude are derived from GPS, not from movement through the air."
    I wasn't saying to use the android as a standalone EFIS; I was saying to add the pressure sensor hardware to a Stratux (and add the code to the Stratux to send the data) and add the code to the app of choice on the android device to display the data from the Stratux.
     
  8. Jun 21, 2019 #48

    CharlieN

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    Yes but, whatever is driving the display in the Droid needs to have the pressure derived feed added so it can show and logically calculate this vital information.
    Plus the real value is to have a script to compare the air derived information to the GPS info. This will be of great value.

    I did a search on EFIS for tablets and came up with one that looked good in that it used a sensor box, unfortunately that sensor box is about $900 usd. Kind of defeats the purpose here when Stratux designed hardware is very conservative price wise.

    I have a local young guy who can write code, I am well into my 60s such that these languages are just foreign to me.

    To make the Raspberry output to the display should not be all that hard unless laying out the graphics is harder than he demonstrated to me last year.

    And yes on the $100 display, I have not looked at how many Nit they put out so far as to be sunlight readable, the $100 units might just be junk.
     
  9. Jun 21, 2019 #49

    Geraldc

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  10. Jun 21, 2019 #50

    CharlieN

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  11. Jun 21, 2019 #51

    spaschke

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    https://www.openflightsolutions.com/ has a stratux box with static port for altitude. I read they are working on pitot port for ias. I think it is around $240.
    https://westphae.github.io/stratux/ is an open source software project that is a fork of the cyoung/stratux project and is working on pitot and static ports also.
    https://mw-avionics.com/ Mountain Wave avionics has a "stratux" type custom board with pitot and static ports
    Jose and Erik from Basic Air Data in Italy have an open source design "air data computer" based on the teensy microcontroller. It does not have ADS-B.
    There are at least 3 other commercial products and open source projects also that I have run accross. Most are on GitHub.
    All these people have a "stratux" type computer that will work with the EFBs giving the data needed for very little money.

    I have built a stratux box for $80 a few years ago. I am presently building the Basic Air Data air data computer. I am also developing a Nav radio using SDR, which will be a stepping stone to a VOR display and maybe ILS in the future.

    If you have a display on the stratux box, you will just see a linux console, if I remember correctly. I did it a couple years ago. It is just a data processor with sensors, SDR and a wifi server. It sends a serial stream of data over wifi. The graphics are on the tablet app.

    a hud can be done with just a phone or tablet and a mirrored film on the windshield. Run an app that will reverse the tablet display. OR Buy a cheap projector that will plug in to the raspberry pi or tablet to be a 2nd display or get a more expensive projector that can be a wireless 2nd display. I've read that you can run android on a raspberry pi.
    People have built HUDS for a few hundred dollars.

    Steve
     
  12. Jun 21, 2019 #52

    BJC

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    What is a Nav radio?


    BJC
     
  13. Jun 21, 2019 #53

    spaschke

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    sorry, NAV/COM Radio
     
  14. Jun 21, 2019 #54

    BJC

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    Asked half in jest; I have two nav/coms, and never use them for navigating. Are VORs still being decommissioned?

    That leaves the ILS. I would be reluctant to put much trust in a localizer / glide-slope receiver that I built myself.

    There could be a market for two Coms in one box.


    BJC
     
  15. Jun 21, 2019 #55

    spaschke

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    I thought you were joking. :D
    I imagine VORs will be disappearing soon. I'm doing it mostly for the learning factor. No, I don't want to pay thousands of $ for an AM receiver, but that is secondary to learning SDR programming. SDR transmitters are starting to show up. Who knows, our comm radios could consist SDR sticks connected to the next raspberry pi in the future.;)
    BTW, localizer / glide-slope receivers are just comparing the signal strength of two (I think or is it 3) frequencies. Much easier math than digital voice communication
     
    Last edited: Jun 21, 2019
  16. Jun 21, 2019 #56

    blane.c

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    You can still NAV to AM radio stations with an ADF receiver. Also Russia has 3 or 4 VLF transmitters that a VLF OMEGA should work on. Of course who would want to or have a reason to use a system that didn't tell the world your position while you were driving. Ha ha.
     
  17. Jun 21, 2019 #57

    Blackhawk

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  18. Jun 22, 2019 #58

    rv7charlie

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    CharlieN, what you wrote in post 48 is what I've been saying in my last few posts.

    All,

    HUDs need to be focused on infinity to be truly effective in the cockpit. According to some of the guys over on VAF, the Hudley sorta almost works, but focuses near the prop. Apparently, proper focus distance is hard (read, expensive).

    Edit: the dedicated display someone linked earlier showed up as costing ~$300. Seems a bit pricy when a good-enough android tablet can be had for ~$75.
     
  19. Jun 22, 2019 #59

    282ex

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    https://github.com/JohnMarzulli/StratuxHud
     
  20. Jun 22, 2019 #60

    Hephaestus

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    Suppose this is where I say, this is where that AR glasses solution belongs, beam the HUD to the glasses. ;)
     
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