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Admiralty chart with LED sequences

Discussion in 'LEDs and Optoelectronics' started by tinmadlad, Sep 17, 2012.

  1. tinmadlad

    tinmadlad

    6
    0
    Sep 17, 2012
    Hey Everyone,

    Looking for some advice on how to tackle a project.

    I am looking to make a decorative wall chart for my home but with an extra dimension. I would like to frame a standard Admiralty paper chart (the type sailors use to navigate) and hang it on my wall.

    Something like this:

    [​IMG]

    In marine navigation, you use the lights of lighthouses or cardinal marks to know what your position is at night. These beacons all have their own unique colour and flashing sequence.

    You can see the details of the seq. - For example Racon(K), the sequence says Q(3)10s11m8M.

    This means: Q (quick flashing~ 30-50 flashes per minute) - 3 flashes, repeading every 10 seconds. The 11m means its 11 meters above the water level and can be seen 8 nautical miles away (8M).

    I am looking to design an LED system that will flash according to this sequence and then do one for all of the beacons on my chart, all controled by a single switch so that I can turn it on and it will flash for decorative purposes.

    Could anyone point me in the right direction as to where to start with this. I have access to all the materials I need and have a basic understanding (high school engineering) of circuitry.

    Thanks in advance.

    Tinmadlad
    tinmadlad-at-gee-mail-dot-com
     
  2. CocaCola

    CocaCola

    3,635
    4
    Apr 7, 2012
    You could do this with a bunch of 555 timer circuits, but I would personally just do it with a micro, just set the flash rate of I/O pins accordingly... Since 100% precision isn't needed (I assume) this can be done with basic software no need to get into hardware level timers and the such...

    How many different lights are we talking about?
     
  3. tinmadlad

    tinmadlad

    6
    0
    Sep 17, 2012
    Thanks for the reply!!

    I haven't decided what chart I'm using but I would say no more than 15 lights.

    What micro would you suggest and is it as simple as programming each pin, and wiring the LED (and perhaps a resistor) to each pin and switching it on?

    Tinmadlad
     
  4. CocaCola

    CocaCola

    3,635
    4
    Apr 7, 2012
    I primarily use PIC micros, as for what one I would not pick that until I knew all the perimeters of the project... The number of lights would play into the design and how I would go about it... I might do a pin for light configuration or I might go with and LED driver chip...

    In theory yes that is the basics of it, but there is a little more in practice... Best to buffer the I/O lines with transistors in many applications, and there has to be a programming 'logic' devised to get the proper blink patterns...
     
  5. tinmadlad

    tinmadlad

    6
    0
    Sep 17, 2012
    Ok great, thanks for your help.

    I don't understand alot of the terms you've used:

    Is there any online tutorials you would suggest for getting me started?

    Thanks!

    T
     
  6. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,175
    2,690
    Jan 21, 2010
    If you don't understand the terms, and you're only building one of these, you may be best off googling "PICaxe" and following that lead.

    You would start by writing a program to flash a single LED (just to cut your teeth on it) and then there are some techniques I would use to flash multiple LEDs at different rates.

    To make them look realistic, you would probably vary the timing very slightly between the different "lighthouses" so they didn't stay perfectly in sync (as they almost certainly don't in real life).

    So if you're interested in this approach, get a PICace chip with at least 15 I/O pins and the extra stuff you will need to prototype (a programming cable, programming software, a breadboard, some LEDs and some resistors (start with a couple of 220 ohm resistors). The small 8 pin chips are convenient to learn on, and they're cheaper, so you can afford to make some mistakes with them. After you're comfortable with the process, move to the larger chip with the confidence that you know what you're doing.

    You could also do this with an Arduino. If you have heard of either of these before, or especially if you know someone who has worked with them, you might choose one over the other. The mechanics of programming them are similar, however the software is very different. Both are widely supported on the internet by many sites and indeed forums.
     
  7. gorgon

    gorgon

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    23
    Jun 6, 2011
    Just some questions.
    Isn't the different lights sectorized, with different colours in each sector?
    Will you mask the different colours, and use white LEDs only?

    TOK ;)
     
  8. tinmadlad

    tinmadlad

    6
    0
    Sep 17, 2012
    Steve, thanks a million - Looking forward to giving it a try!

    Gorgon - what do you mean by sectorized? Do you mean that depending on the direction you are looking the light will appear a different colour? That is the case on a boat (i.e. to determine port/starboard) but not on light houses/ cardinal marks.

    I was just going to use red LEDs for cardinal marks and white for light houses... this is for decorative purposes - i doubt anyone would want to go sailing using it as a nav tool!!
     
  9. gorgon

    gorgon

    603
    23
    Jun 6, 2011
    I was only asking to know the degree of realism in your display. Just curious.

    And yes, I meant that some lighthouses/marks display sectors/zones with different colours, maybe the smaller ones.

    You could make a cluster of small LEDs simulating a rotating lighthouse, but that might be outside your scope. :D

    TOK ;)
     
  10. tinmadlad

    tinmadlad

    6
    0
    Sep 17, 2012
    Some lighthouses alternate between say white and red to emphasise caution. I don't see how this would be any harder to do (by putting two LEDs one red one white) beside eachother, and having them firing on alternate timings. For example, if the sequence was AlFl WR 10s (Alternating Flashing, White/Red every 10s) Couldn't I just have a white and red on 20 second lighting patterns, 10 seconds apart and then put them beside eachother on the chart??

    Anyway, I was looking for somewhere to start and have that! I'll check back in when i have a finished product!

    Thanks for all the help!

    Tinmadlad
     
  11. tinmadlad

    tinmadlad

    6
    0
    Sep 17, 2012
    I think I get what you mean here, but when you consider the amount of space you have to work with on a chart the size of say Boston Harbour - well then you would only have the width of an LED poking through the map in the place of the lighthouse to work with!
     
  12. BobK

    BobK

    7,601
    1,643
    Jan 5, 2010
    You could use and RGB LED at each site, but then you would have 3 times as many control signals.

    Bob
     
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