Arduino altimeter & airspeed indicator

Discussion in 'Instruments / Avionics / Electrical System' started by cluttonfred, Apr 8, 2015.

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  1. Apr 10, 2015 #21

    Aviator168

    Aviator168

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    Someone here wants a backup. My preferred method is send the data to a tablet for display. If you want redundancy, make two units and send both data to the same tablet or send all data to more than one tablet. If you organize your data into multiple pages, you can have one tablet displaying one set of the data and another displaying another set. If one tablet dies, no big deal, just flip through all the pages on the remaining tablet(s). The whole setup shouldn't cost you more than $500.
     
  2. Apr 14, 2015 #22

    cluttonfred

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    For what it's worth, I have gone ahead and ordered an Arduino kit to start messing around and learning the technology. Eventually, I'd like to use one of the miniaturized Arduino boards and a barometric/temperature sensor to make a very simple, clear ALT/VSI. One idea would be to use a 7-segment or alphanumberic display for the ALT and a simple bi-color graphic matrix (or two monochrome ones) or even segments of an single oversize alphanumeric character for the VSI indicator.


     

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    Last edited: Apr 14, 2015
  3. Apr 14, 2015 #23

    Aviator168

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    Don't understand why you have to control the display? Just make sure the display you get already comes to the driver circuit. Otherwise, it is just a pain in neck to figure out with segment to lit up.
     
  4. Apr 14, 2015 #24

    cluttonfred

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    Yes, I would use displays already configured for serial control.
     
  5. Apr 14, 2015 #25

    Aerowerx

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    Keep in mind that Yellow on Black is the most visible color combination.
     
  6. Apr 14, 2015 #26

    cluttonfred

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    I need to find some comparisons of readability of various types of display in direct sunlight. I am thinking that LED or OLED displays behind a thin, tinted anti-reflective cover might work well.
     
  7. Apr 14, 2015 #27

    FritzW

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    Are there supposed to be pictures on message #22?
     
  8. Apr 14, 2015 #28

    cluttonfred

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    Yes, fixed.
     
  9. Apr 15, 2015 #29

    cluttonfred

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    I would love some feedback from folks on what you'd consider to be the minimum acceptable instrument format. By that I mean that a pure digital readout (just numbers) is not very satisfying, so I am thinking that some sort of analog indication would be nice as well. It could be a horizontal or vertical bar graph, a circular graph, a changing icon in a matrix, or something else. Ideally, I'd like to come up with a standard format adaptable to multiple types of gauges so I could have faceplates CNC routed or even 3D printed.

    One interesting development is the "Neopixel" type of LED, which each have a tiny chip inside and can be individually controlled for brightness and color by a single data stream. I can imagine a ring of such LEDs behind a translucent faceplate and with a small OLED screen in the middle to show almost anything, just the software and labels on the faceplate would change. Color-coding the LED indications would make it easy to distinguish between gauges at a glance.

    x1586-00.jpg.jpg x938-15.jpg.jpg
     
    Last edited: Apr 15, 2015
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  10. Apr 15, 2015 #30

    cluttonfred

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    I found one! In addition to the simple monochrome LCD design in my first post, here's a nicer one with a color screen developed by a French microlight instructor.

    Aviation altimeter for microlights

    alti.jpg
     

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  11. Apr 15, 2015 #31

    Aviator168

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    Analog display is always more intuitive; but it is more difficult to implement.
     
  12. Apr 16, 2015 #32

    bmcj

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    Yes, but chartreuse green and day glow orange are the most annoying combination! :gig:
     
  13. Apr 16, 2015 #33

    cluttonfred

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    That can be for the low fuel warning indicator! Seriously, though, I am beginning to think that a ring of neopixel smart LEDs around a simple LED display, maybe just a four-character alphanumeric, all behind a tinted anti-reflective acrylic or polycarbonate faceplate, might work very well. Two alphanumerics, to make a 4x2 character display for dual gauges, would be even better, but I haven't found the right size modules yet. The color of the alphanumeric display would be determined by what is the brightest and easiest to read in sunlight, the neopixels can change to any color. You can imagine that the same display could be used for ALT, ASI, VSI, RPM, etc.

    gauge mockup neopixel alphanumeric.jpg
     
  14. Apr 20, 2015 #34

    cluttonfred

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    For this project, does anyone know of a source for empty instrument or gauge housings with or without front bezels? Obviously, something like that would make this much easier.

    It would also be perfectly possible to use the same setup to drive stepper motors to turn the dials on mechanical gauges. in fact, it might even be easier than the digital, since there are add-on shields (superimposed accessory boards for Arduino) that can control multiple servos with ease. A clock-type double pointer for the altimeter would be harder, but a single pointer would be easy. A second servo turning a small disk behind a hole in the main dial could provide the VSI reading.

    Would there be interest in an analog gauge option, perhaps styled something like these?

    F31765969__38578.jpg
     
    Last edited: Apr 20, 2015
  15. Apr 20, 2015 #35

    Blue Chips

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    "does anyone know of a source for empty instrument or gauge housings with or without front bezels"

    Several months back I came accross a site that had them, they had to be purchased but they were not expensive.
    Went to locate that site a few weeks later, hunted for quite some time and never did come accros them.

    Only mention that to say they are out there if you can find them.
     
  16. Apr 20, 2015 #36

    don january

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    just a suggestion. Craigs list always has used instruments dirt cheap, maybe you can find what you need and strip one out for your purpose?
     
  17. Apr 20, 2015 #37

    cluttonfred

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    Thanks, Blue Chips, I'll keep looking. don january, that sounds fine for just one, but I am hoping to make a prototype which would then be offered open-source for anyone to copy or perhaps I'd get into selling little kits. Either way, I'd be looking for a something that could easily replicated so all the parts have to be easily sourced.
     
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  18. Apr 20, 2015 #38

    don january

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    The first place I would go to look would be a local auto parts store. the hub caps on alot of newer cars have a incert that go in the middle of the hub cap to cover the spindle housing. there 2 1/2 to 3 1/2 dia and are of hard plastic and most have 3 mounting points. Or maybe something like a distributor cap? Check Toys-R-Us maybe theres a simple kids toy that will work ? Who knows but I'll keep my eyes open for you. Don
     
  19. Apr 20, 2015 #39

    12notes

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    You don't need a shield for this, just connect the + & - of the servo to power, and the control pin straight to a digital pin on the arduino. The servo library can handle 12 motors on an Arduino Uno (mini, micro, and nano are the same), and 48 on the Mega.
     
  20. Apr 20, 2015 #40

    cluttonfred

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    Thanks, guys. 12notes, I am new to Arduino and not very strong in electronics generally, just interested in learning. I see what you mean about the digital pins, though I see that only 6 of 14 provide pulse-width modulation on the Uno, does that make a difference? I also think that I would need a stepper motor for a single-pointer altimeter (goes around the dial twice to indicated 20,000 ft on a 10,000 ft dial). I am still unsure about the actually capacity of something like the Uno to do everything I want--ideally, I'd like to have ALT, ASI, VSI and perhaps even GPS from a single control unit with multiple displays. But I am determined to learn!
     

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