SNS---Simple Navigation System idea

Discussion in 'Instruments / Avionics / Electrical System' started by Aerowerx, Jul 19, 2017.

Help Support HomeBuiltAirplanes Forum by donating:

  1. Jul 19, 2017 #1

    Aerowerx

    Aerowerx

    Aerowerx

    Well-Known Member

    Joined:
    Dec 1, 2011
    Messages:
    4,974
    Likes Received:
    1,354
    Location:
    Marion, Ohio
    I was thinking about this this morning.

    A simple nav system made of an Arduino, GPS board, 16x2 LCD display, and rotary encoder knob.

    You enter the coordinates of your destination and it tells you the bearing.

    Can't get much simpler. Of course, I am already seeing some feature creap. Like the distance and your course.

    The simple version would only require simple trig. No great circle calculations etc.

    There are all kinds of Arduino nav systems on the internet, but they all seem to be moving map displays.
     
  2. Jul 19, 2017 #2

    gtae07

    gtae07

    gtae07

    Well-Known Member

    Joined:
    Dec 13, 2012
    Messages:
    1,802
    Likes Received:
    1,074
    Location:
    Georgia
    Why? I've used a GPS that displayed only bearing, distance, and groundspeed. It was great at the time, but that was compared to a paper sectional on a hazy day. A simple android device running Avare would cost only a bit more (if you have to buy the device) and be far superior.
     
    Topaz likes this.
  3. Jul 19, 2017 #3

    cluttonfred

    cluttonfred

    cluttonfred

    Well-Known Member

    Joined:
    Feb 13, 2010
    Messages:
    6,358
    Likes Received:
    2,228
    Location:
    World traveler
    It's a neat idea, but my explorations have shown me that anything more than a one-trick pony device starts to become complex and expensive enough that you can do it better and cheaper with an Android phone or tablet and an app or two such as the one Gipsi offers: http://gipsiapps.com/
     
    Topaz likes this.
  4. Jul 19, 2017 #4

    BoKu

    BoKu

    BoKu

    Well-Known Member HBA Supporter

    Joined:
    Aug 16, 2013
    Messages:
    2,301
    Likes Received:
    2,877
    Location:
    Western US
    I've tried to use a smartphone in the cockpit. Epic fail; I could barely read the darn thing. Real cockpit-designed nav displays have the capacity to display very brightly so you can actually read them in sunlight.
     
    cheapracer likes this.
  5. Jul 19, 2017 #5

    Pops

    Pops

    Pops

    Well-Known Member

    Joined:
    Jan 1, 2013
    Messages:
    7,102
    Likes Received:
    5,998
    Location:
    USA.
    Back in the 1980's my son designed, built and programed a nav system that was like a GPS but measured the magnetic lines of the earth in different vectors to establish a position. The changing of the magnetic north and south poles were programed in . The only thing that you had to do to set up is press and northern or southern hemisphere button. Yes, it worked.
    I designed and built all the PC boards for the computer for him at the time.
     
  6. Jul 20, 2017 #6

    TFF

    TFF

    TFF

    Well-Known Member

    Joined:
    Apr 28, 2010
    Messages:
    11,624
    Likes Received:
    3,264
    Location:
    Memphis, TN
    That's how the original in rout GPS and Loran worked. I know a couple of planes still with them.
     
  7. Jul 20, 2017 #7

    pictsidhe

    pictsidhe

    pictsidhe

    Well-Known Member

    Joined:
    Jul 15, 2014
    Messages:
    6,833
    Likes Received:
    1,832
    Location:
    North Carolina
    How did it do longitude?

    Good point on sunlight readable phones Boku, I have an app so i can shake my phone to answer as it's impossible to see the slide thing in sunlight.
    On the OT, I'd be tempted to use four push switches. Push one way for one ordinate to change one way, the rate of change speeds up the longer you hold it. This can work well if tuned right.
     
  8. Jul 20, 2017 #8

    Aerowerx

    Aerowerx

    Aerowerx

    Well-Known Member

    Joined:
    Dec 1, 2011
    Messages:
    4,974
    Likes Received:
    1,354
    Location:
    Marion, Ohio
    I was thinking of a rotary encoder with integral push button. Push the button to select a digit. Twirl the knob to change it.
     
  9. Jul 20, 2017 #9

    Aerowerx

    Aerowerx

    Aerowerx

    Well-Known Member

    Joined:
    Dec 1, 2011
    Messages:
    4,974
    Likes Received:
    1,354
    Location:
    Marion, Ohio
    Exactly what brought this to mind. The c172 I soloed in had such a Loran, but you entered the ICAO identifier instead of coordinates.
     
  10. Jul 20, 2017 #10

    Aerowerx

    Aerowerx

    Aerowerx

    Well-Known Member

    Joined:
    Dec 1, 2011
    Messages:
    4,974
    Likes Received:
    1,354
    Location:
    Marion, Ohio
    Why I was thinking of a simple B/W LCD display.
     
    cheapracer likes this.
  11. Jul 20, 2017 #11

    Aerowerx

    Aerowerx

    Aerowerx

    Well-Known Member

    Joined:
    Dec 1, 2011
    Messages:
    4,974
    Likes Received:
    1,354
    Location:
    Marion, Ohio
    Why, you ask? Because we can.

    Why build our own planes? Same logic.

    Such statements have always amused me. If you want something,go buy it. But if you want the fun and learning experience of DIY, what's wrong with that?
     
    akwrencher and Vision_2012 like this.
  12. Jul 20, 2017 #12

    Aerowerx

    Aerowerx

    Aerowerx

    Well-Known Member

    Joined:
    Dec 1, 2011
    Messages:
    4,974
    Likes Received:
    1,354
    Location:
    Marion, Ohio
    But this would be a one trick pony. Guessing less than $50 in parts.

    And I refer you to my previous post for the remainder of my response.
     
  13. Jul 20, 2017 #13

    pictsidhe

    pictsidhe

    pictsidhe

    Well-Known Member

    Joined:
    Jul 15, 2014
    Messages:
    6,833
    Likes Received:
    1,832
    Location:
    North Carolina
    Feature creep: Instead of a bearing, it tells you the desired heading relative to your current heading, an arrow saying 'that way'. Without that, you need to read the bearing then look at your compass. A simple arrow is going to be much easier to follow and would be preferable to me. This feature works badly at walking speed and hopeless when stationary, but even a slow 103 is going fast enough for it to be very good.

    I'd also be really tempted to have ground speed, distance to target and maybe time to target at current ground speed. If it senses when you are stationary, a different display would be helpful.
     
  14. Jul 20, 2017 #14

    Dana

    Dana

    Dana

    Super Moderator Staff Member

    Joined:
    Apr 4, 2007
    Messages:
    8,600
    Likes Received:
    2,992
    Location:
    CT, USA
    Granted it'd be easy to do with an Arduino, but I can think of a lot more interesting Arduino projects than replicating something that has been available off the shelf dirt cheap for years now. Of course that's coming from a guy who programs only in self defense when nothing else is available and/or the other guy's code doesn't work. But if you must, learn Java and do it as a barebones smartphone app, hardware cost zero.

    Dana
     
  15. Jul 20, 2017 #15

    Aerowerx

    Aerowerx

    Aerowerx

    Well-Known Member

    Joined:
    Dec 1, 2011
    Messages:
    4,974
    Likes Received:
    1,354
    Location:
    Marion, Ohio
    See post #11.

    Also a problem with reading a smartphone in sunlight.
     
  16. Jul 20, 2017 #16

    Aerowerx

    Aerowerx

    Aerowerx

    Well-Known Member

    Joined:
    Dec 1, 2011
    Messages:
    4,974
    Likes Received:
    1,354
    Location:
    Marion, Ohio
    I've thought of those ideas, but was trying to keep the math simple.

    For speed, distance, and time you would have to know how big the earth is. For more than a few hundred miles you would need to do great circle calculations to get any amount of accuracy. Unless taking a path 10 or 15% longer is ok ( just guessing, but you get my meaning).
     
  17. Jul 20, 2017 #17

    pictsidhe

    pictsidhe

    pictsidhe

    Well-Known Member

    Joined:
    Jul 15, 2014
    Messages:
    6,833
    Likes Received:
    1,832
    Location:
    North Carolina
    Great circle calculations aren't that hard, or does an arduino lack a decent math library? I had to write my own math library for the PIC 20 odd years ago after discovering it was under endowed. That was much, much harder than the trig I wanted to do with it.
     
  18. Jul 20, 2017 #18

    Aerowerx

    Aerowerx

    Aerowerx

    Well-Known Member

    Joined:
    Dec 1, 2011
    Messages:
    4,974
    Likes Received:
    1,354
    Location:
    Marion, Ohio
    Well, according to the Arduino math.h documentation, there is a full set of trig functions, including hyperbolic trig.

    Its been a while since I looked at great circle calculations, but I believe that is all you need.
     
  19. Jul 20, 2017 #19

    spaschke

    spaschke

    spaschke

    Well-Known Member

    Joined:
    Oct 24, 2012
    Messages:
    232
    Likes Received:
    57
    Location:
    Denver, CO
    there are solutions to the sunlight problem - anti-glare screen film & choose the colors wisely.
     
  20. Jul 21, 2017 #20

    Pilotgil

    Pilotgil

    Pilotgil

    Well-Known Member

    Joined:
    Apr 2, 2013
    Messages:
    52
    Likes Received:
    54
    Location:
    Unfortunately California
    I am working on this as a Project "2". It's an Arduino system with a GPS and a basic US airport database - nothing else. It's on a 16X2 LCD (for now), a twin encoder with a pushbutton to enter the airport code. It assumes airport in the US. The database is about 10MB and will sit on an SD card. I do not have the database search working as I have just hardcoded a small subset of the database into the "sketch" with a sequential search (this is not going to work for the entire database) but I have an idea on how to make it simple. I'm just playing with the math right now. No real reason to do this other than "because"...I finished a graphic airspeed, VSI, RPM, hourmeter, dual EGT, water temp and pressure, volts and amps (obviously a Rotax engine) as well as a RTC approach/local clock and all are flying well over the last two years; however, I need to add fuel pressure now (to monitor the vacuum driven fuel pump) to Project "1" so the Simple Nav will wait until that is done. Because the fuel pressure level are only 2.5 to 5 psi, I'm still working on finding the sensor.
     

Share This Page

arrow_white