Aircraft Lighting System - Ground Floor Development

[Gary Warner]

A friend of mine has been bugging me (more like hounding me) to make a LED lighting control PIC project. I though I'd air out the ideas here and get feedback as to what would be best done in the project before actually making it.

These are my thoughts:

It should be able to control all normal lights on airplane (position, strobe, beacon and others).

It will be fully programmable with an external device that does not need to be hooked up to the controller while setting the modes. I.E., be able to completely setup modes and operations in-hand before moving the data to the on-board controller.

PC interface was considered, but was dropped in favor of a stand-alone programmer (ease of field and shop programming). One programmer will be able to run with any of the controllers (buy 5 controllers and only need one programmer).

The on-board controller should have options to be controlled by an aux channel(s) from the receiver.

Lighting options should be for both incandescent and LED lights.

A large library of flashing sequences, rates and flash orders will be available.

Options to change most flashing sequences by the user.

On the hand-held programmer, the face if it will include a drawing of a plane with LEDs representing the positions of lights will aid in setting up modes.

Considering an LCD display for intuitive programming. If not, an intuitive method using mode LEDs and/or 7-segnalt displays.

What else???

Gary
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[Malc C]

Gary, my 2p worth !

There are several options already on the market, some commercial, some semi-commercial and others home made. These include the option to programe different patterns, from the PC, which are stored in the PIC. Others, like the one I came up with is a simple design that produces a repeated flash pattern over and over again.

The other thing to think of is weight. Whilst your device, with its LCD display or whatever may look cool, it will be of interest to those with models large enough to carry the weight, and to accomodate. Keeping the unit small, simple and light weight will appeal to a more wider customer base, including those with smaller electric powered models.

I'm not saying you shouldn't design your product, but I don't see any point in re-inventing the wheel. I'm sure a quick search of this forum and the net will throw up some existing designs.. if not I'm sure I can drag out some bookmarks

[Gary Warner]

Gary, my 2p worth !

There are several options already on the market, some commercial, some semi-commercial and others home made. These include the option to programe different patterns, from the PC, which are stored in the PIC. Others, like the one I came up with is a simple design that produces a repeated flash pattern over and over again.

The other thing to think of is weight. Whilst your device, with its LCD display or whatever may look cool, it will be of interest to those with models large enough to carry the weight, and to accomodate. Keeping the unit small, simple and light weight will appeal to a more wider customer base, including those with smaller electric powered models.

I'm not saying you shouldn't design your product, but I don't see any point in re-inventing the wheel. I'm sure a quick search of this forum and the net will throw up some existing designs.. if not I'm sure I can drag out some bookmarks

Malc C,

I know they are already available, but the loaf of bread has been done too. I like making my own bread from time to time ;).

Weight would be <1oz and about an inch cuded. The hand-held programmer would plug into the controller via 3 or 4 wire plug to download the programming. I'm even now, doing some experiments with inductive data transmissions. A small coil would be placed under the skin of the plane and the programmer would have a coil that was placed over the coil in the plane. If my experiments work out, it would be a wireless (non-rf) solution. How cool would that be ;)?

Maybe IR?

Gary
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[Malc C]

Gary,

Fair point, and it sounds like you have some neat ideas. I didn't get the point that you are thinking of a two part device, one on the model, the other a hand held device that you could configur and then upload to the model (I had the image of a board with a large 16 x 2 lcd panel fitted to a micro heli :) )

I'm even now, doing some experiments with inductive data transmissions.

Not been working with any artificial rocks in Russia recently ;)

Tell you what I would like to see. A cheap data aqusition system that could capture flight data (amps, volts for electric, and possibly motor rpm for a glo powered) and then be interrigated by a hand held device for display, or saved an uploaded to a PC. Yes I know its been done before, and there are commercial units, but they cost the earth.. now if there was a complete "model flight computer" that incorporated both your idea of programmable nav lights, and a data recorder.. and be cheap then you might be on to something :)

[Gary Warner]

What do you think would be a 'fair' price for a device that records Volt and amps? What would be a fair price for additional items that would require additional sensors? Altitude, speed, G's, etc. sensors can get a bit expensive compared to the PIC cost alone for volts and amps.

I've seen the Eagle Tree thing - it's too much for me.

Some neat I2c eeprom Ic's have been coming out with large memory. Even a SD/MMC could be useful (can be removed and plugged directly into your PC).

As it is, for what I have, it's $16 cost just in Ic's to make a 64KByte memory card. What's more, like the RAM, RS-232 at 4800 baud takes like 3+ minutes to download a full data set.

Though I can code PIC well, I don't have much luck with complicated VB or VC++ programs. I can do little one-off programs, but nothing commercial ready. I'd need the assistance (read: do it all for me) of a real code-head to pull this one off. (wink-wink)

Gary
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[Malc C]

I'd need the assistance (read: do it all for me) of a real code-head to pull this one off. (wink-wink)

No good looking at me... I still struggle with the coding of the PIC :) - Flashing a few LEDs is one thing, data logging etc is something else !

I agree that once you start adding air speed sensors, g force meters and altitude sensors things get expensive, thats why I would stop at just the basics, like volts, current, rpm of motor (monitor the prop) or rotor speed if a heli.

As for cost.. thats a hard one.. we all know how much PCB's cost on a small batch run, or the hassle in making them yourself, then there's the componet cost..you could be looking at £50 minimum per unit before you've factored in the labour.. assuming you want to make these as a means of supporting your hobby.

[Gary Warner]

This is kind of what I have in mind for the hand-held programmer. The LEDs are addressed by their numbers and turn on or off in real time as programmed.

[Eddy]

Do it with real flash tubes, even the bright led's are not bright enough,
I will take one if you do it with flash tubes.

[Gary Warner]

Do it with real flash tubes, even the bright led's are not bright enough,
I will take one if you do it with flash tubes.

I've had bad luck with RFI and flash tubes in the past. Things may have improved today, but I don't know that. Plus, if I remember right, they can suck up the power.

Gary
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[Gary Warner]

Here's what I'm thinking for basic menu flow on the programmer:

Gary
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[Malc C]

Just a comment, LEDs 1 and 2 (the red / green port / starboard) lights on a real plane / heli remain constant, so there would be bo need for these to be included in the programming options, unless you are not modelling true navigation light configs.

Flash (zenon) would be cool, but the high voltages and power consumption to flash 4 - 5 tubes at once could cause a power drain on the flight pack. Adding additional batteries to a model just to run the navigation lights would not be practical in most models due to the weight (unless you're making a 1/9th scale 777 or Airbus ! However there are some LED arrays (lexcon I think they are called) that can be seen in daylight, and offer a wide viewing angle.

[Gary Warner]

I agree about the nav lights. Maybe yes or no. I'll take that into consideration when I make the library files and probably allow the user to change it if they want to.

I also agree about the xenon lamps unless they are available in smaller sizes and lower ratings. Maybe I'll make an additional add on xenon flasher driver board that would take the LED info and drive the xenon lamps if a user wanted to use them, on an aux battery source.

Gary
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[JohnMuchow]

You can get incredible bright pulses from these higher-power LEDs as long as you observe the current vs. duty cycle ratings. Bright enough to rival flash tubes. And you get to avoid the high voltages and other downsides to having a flash tube driver nearby your other electronics.

Might be worth exploring.

[Gary Warner]

Thanks John. I knew there were current/time limits. I had no idea that they could rival xenon lights. Thanks for the tip. I'll see what I can find on this.

Gary
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[Malc C]

There was a video link posted in one of these threads where someone used lexon (sp) array as the strobe, which were bright enough to be seen on an overcast day.. Not sure what battery pack was used, but the Airbus it was fitted in to was huge. Gave all the brighness of a strobe, but without the high voltages or RF interfearance associated with normal zenon strobes

[Gary Warner]

I saw that video too. That was a very nice plane and the interior lights were a nice touch.

I'll do some checking on the lexon lights.

Gary
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[Tomapowa]

The ultimate (and rediculously programmable) LED flasher/sequencer for Nav lights... uses your PC to program sequences and servo controls...

http://diyrc.com/RC-14c.html