LED lighting for airliners anyone?

[armored76]

Hi,

 

I gathered some components for eventually lighting up some of the models I'm going to build but never actually got around to do much with it except a few trials. To help with that, I wanted to ask you guys if someone would care to join in brainstorming some ideas?

 

I was thinking, civil airliner lighting is pretty much standardized across airlines and models so, maybe we could start with these?

 

Let's see:

• what are the standard lights?
• what colours would the lights have
• which ones are static (on/off) and which ones dynamic?
• which lights would be on in different stages?
  • at the gate
  • taxiing
  • during take off
  • in-flight
  • during landing

 

If it helps, we can start with a particular type like an A320 or 737...

 

Eagerly waiting for your feedback!

Cristian

[picard]

That's a terrific idea sir. As a lump of stuff only just crawling out of the swamp when comes down to lighting up small stuff, I have several projects on hold waiting for my tiny brain to catch up with various stuff and things.

 

SF plug and play kits can get quite pricey indeed which completely understandable, but have always wished to do fully active and lit airliners, I must admit. So any sources and blatant caveman advice is always gratefully received.  

I saw a Utube video with this excellent chap a few months ago from the Telford show I think? And although quite a few beer tokens per kit they do seem all dancing and singing.  Cheers. 

 

https://www.magicscalemodeling.com/shop/Civilian-airliners-c22677068

[armored76]

Thanks for the link and your interest in the topic

 

Those kits are a bit pricey, indeed but they need to be developed after all which explains (part of) the price.

 

I'm currently thinking along the lines of an Arduino (Nano?) board with extension boards that would offer, for instance:

• 8/16/24/32 independent LED channels
• 2/4 DC motor control channels
• sound control (SD Card holding the sound files)
• Bluetooth for smartphone connection

For the control boards we have the option of using ready-made ones or develop our own. Commercial boards are easier to start with but have shape limitations. Custom boards can be shaped to the project requirements but are harder to build.

 

This is all very crude right now, barely listing up possible options. We can start "small" with LED control and extend from there.

 

I can bring in hardware and software knowledge but will need help with the rest

[armored76]

Let's get more concrete...

References seen so far would suggest the following light on commercial airliners:

 

• taxi lights on the nose gear strut (white) - 1 channel
• landing lights on the left and right wing (white) roots - 1 channel
• position/navigation lights on the left and right wing tips and at the tail (green, red, white) - 2 channels
• anti-collision lights on the top and bottom of the fuselage (red) - 1 channel
• anti-collision lights on the wing tips (white) - 1 channel (might be combined with those on the top and bottom)
• alternating landing lights (white) - 2 channels, alternating
• logo lights on the stabilizers (white) - 1 channel
• cabin lighting (white) - 1 channel, LED stripe
• cockpit lighting (white) - 1 channel (might be combined with cabin lights)

I'm counting up to 11 independent light channels to control.

 

Is this list correct/complete? Further suggestions?

 

Thanks!

Cristian

 

PS: An excellent resource on airliner lights: https://aerosavvy.com/airplane-lights/

Edited July 28, 2018 by armored76

[Orso]

Why does the wing tip navigation lights have to be separate channels? Wouldn't they always be lighted at the same time and only need one channel.

How many of the light should always be on at the same time, I thought that many of them could be controlled with a single channel. 

[armored76]

Good point, Björn! However, the red/green can be on while the whites are flashing so at least these two shall be separated.

 

Corrected the list above! Thanks for the feedback!

Edited July 28, 2018 by armored76

[armored76]

Here's another great video explaining lights on an Airbus:

 

 

Source: Youtube.com

[armored76]

I think I'm going to use the following components, mainly because these are widely available as break-out boards (ready-made PCB with components assembled) but can also be built into a custom board:

• Arduino Micro Pro - the "heart" of the whole system, controlling the LEDs, on/off, brightness, blinking pattern, etc
• PCA9685 - 16 channel PWM control module allowing for on/off and brightness control of up to 16 channels
• ULN2803A - Darlington array allowing to control up to 500 mA per channel; might be overkill in most cases but is required for LED stripes, for instance

The circuit above would allow for up to 16 control channels. If 11 or these are used by the LEDs, 5 still remain open as reserves. These could be used to control 5 (fixed rotation sense) or 2 (changeable rotation sense) DC motors, for instance.

 

I'll try to upload a first sketch over the next few days.

 

Thoughts? Comments? Questions?

 

Cheers,

Cristian

[HP42]

Great thread chaps. A nice kit than can be adapted for lighting is the Genie used in schools. The boards are inexpensive easy to assemble and the software is free as well as very easy to use. It's used in schools. I've considered adding lights and thought about adding fibreoptics to LEDs using heatshrink. 

https://www.genieonline.com/components/

 

[armored76]

Thanks for sharing, HP42!

 

Indeed, these boards might be an alternative if you already have them. The only problem I see is the rather limited RAM (256 bytes max). I think the Arduino Pro Micro would be a better choice in this case as it is faster, has more program and data memory while being about half the price (or less if order from China).

[armored76]

After some more research I came upon a better alternative to the PCA9685 + ULN2803 combo. The TLC5947 is available as a component as well as a breakout board and will take over the job of the two IC without the need of external component other the LEDs themselves.

 

Hooked up on an Arduino Pro Micro, it can drive up to 24 LEDs (or groups of serially connected LEDs) with brightness control in 4096 steps from min to max.

 

The schematic would then look like this:

<Temporarily removed as it contained a few mistakes. Sorry!>

 

This is just a firs draft version that should work but since I do not have the TLC5947 board yet, I wasn't able to test it or start on the software for this.

 

If you'd care to join in or follow the project more closely, I have create an Easyeda project here: https://easyeda.com/Armored76/model-lighting-kits

 

Please let me know your thoughts! Thanks!

Cristian

Edited August 11, 2018 by armored76

[Will Vale]

Interesting plan. You could use cheaper boards with fewer outputs if you switch to e.g. addressable RGB LEDs, which only need one data pin to drive a string of as many as you want. Although they do tend to come in bigger packages - are you thinking about installing SMD LEDs in wing and fin tips, or running fibre?

Code size shouldn't be a huge issue since airliner patterns are super simple and repetitive, even if you have some kind of ramp up/ramp down, but yeah I think 256b of RAM is quite small if you're not used to embedded programming. For reference, this sequence runs on an ATTiny which has 512b of RAM, and there's some room left over (although I used a fair bit of ROM to store the animation data.) Cost me about 20 USD in components I think, with no bulk discounts. The controller is built around an Adafruit Trinket board.

 

 

Cheers,

 

Will

[armored76]

@Will Vale That looks absolutely amazing!!!

 

I thought I'm pretty much up-to-date with everything hardware components but I had to look up the addressable LEDs They are really nice for a lot of applications. Thanks for sharing the info!

 

If I'm getting this right, you cascade them as any SPI device (DOUT to next DIN) then push 24-bit RGB color data packages at up to 800 kbits/s?

 

Concerning your model, I'm really in awe! The engine flickering, is that a random intensity value on the selected colour superposed on a slower changing one? Would you care to share the maths, please? Also for the display switch-on flicker, if I'm not pushing my luck too much

 

Many-many thanks!

Cristian

[Will Vale]

Hey Cristian, thanks for the kind comments. You're right, you cascade the LEDs although I don't think they use "proper" SPI, it's more a bit-bang protocol where each LED consumes one set of commands (the 24 bit colour) and passes the next on. So you have to update the entire string every frame. I didn't get into the timing for this as Adafruit provide a perfectly good library for it, but it's in the datasheets if you want to roll your own.

 

From memory the superposition just uses a mix of the functions - a smooth triangle wave for the engines plus some noise. It's all 8-bit maths so I probably scaled and added the values in some combination, I'll look tonight.

 

The flicker is probably some sort of thresholded randomness where the threshold changes over time, or maybe the "off" part of the duty cycle changes over time?

 

Cheers,

 

Will

[armored76]

Thank you, Will! If you could share the code or the relevant parts in some way, the would be much appreciated.

 

Of course, if you'd rather not publish it, that is perfectly fine.

 

Thanks!

Cristian

[Will Vale]

Sorry Cristian, I tried a couple of times to post some code and the browser kept crashing. Will see if it works now.

 

So for an engine "throb" I generate a uniform triangle wave by storing scaled time into a byte, and then convert that to a sawtooth like this:

 

byte sawtooth_to_triangle(byte sawtooth)
{
	return (sawtooth > 127 ? 255-sawtooth : sawtooth) << 1;
}

I.e. invert the top half of the range and double to restore the full range. That can then be smoothed by taking a weighted sum with an older value, which gives an OK looking cheap sine-like wave.

 

The noise generator is similar, it runs a timer until it reaches a randomly generated delay, takes the quotient of the time and delay to get an irregular sawtooth wave, and converts that to a triangle wave. When the delay time is reached it generates a new one from the inbuilt 8-bit RNG, masked with a range to control the max wavelength. It's not in any way a high quality noise function (or even a noise function!) but it's cheap to evaluate and doesn't use any floating point maths.

 

For combining the different signalsI tend to either shift and add them to build a weighted sum, or to use a normalised multiplication, like this:

byte mul_norm(byte a, byte b, byte shift)
{
	return ((word)a * ((word)b + 1)) >> shift;
}

The user-specified shift lets you pick the output range you want, to do a straight normalised multiply shift the output by 8 bits.

 

W

[armored76]

Thank you so much, Will! That's genius and simple at the same time

I was thinking along a more complicated "framework" that would accept start and end points for an LED intensity (read: PWM duty factor) or color (read: RGB channel values) plus a transition function like a PT1 delay to go from to the other. Additionally, the noise would be a random adder with a maximum value being a percent of the current value, for instance. But your approach is much simpler and delivers exceptional results, as seen in the video above

 

Thanks again for taking the time to share this! I wish I could give your post more than one "Thanks".

 

Cheers,

Cristian

[busnproplinerfan]

This is something I want to learn, this stuff is completely foreign to me, the set up, which parts etc. Hopefully I can learn something about lighting, mostly for newer airliners. I bought a set of nano LEDs (from evilbay)but they have no wires coming off them, you have to solder them on but they are way to small for me. I saw the ones with the wires after i bought the first ones. That's how it goes I guess.

[armored76]

@busnproplinerfan That's how it often goes, unfortunately Was that any different with the first kits you bought? Have you checked for accuracy, buildability, etc before cashing out for them? I sure did not

 

However, it is no rocket science and with somebody around to ask and guide, it is certainly something everyone can get a handle on. Not everybody is interested in the physics behind LED or the inner structure of a control unit but most of us can build or use a circuit, that I'm sure of. It is about assembling small parts in the right order and with the right orientation (polarity)... does that sound familiar?

 

Here is an excellent article about LEDs to start with: https://learn.sparkfun.com/tutorials/light-emitting-diodes-leds

 

When buying LEDs probably the most important things to look at are color and size. There are 10mm, 5mm, 3mm and 1.8mm packages that have wires included. If these are still too large (and for most models, they ARE too large!), look into the SMD or SMT LEDs. Here you can go as small as 0.4 x0.2mm (so called 0402 (metric) or 01005 (imperial) packages). Personally, I think anything smaller than 1.6x0.8mm (so called 1608 (metric) or 0603 (imperial) packaging) is very hard to solder so, in case you need any of these let the pros do it and buy LEDs that have soldered wires. Ebay sellers offer these rather often but check the reviews to make sure the quality is right.

 

In case you decide to solder your own wires, there are some great Youtube videos to show you how. Grab a package of 100 pieces, some 0.2mm magnet wire, a ceramic tile some double-sided tape solder (or even better, solder paste) and a temperature-regulated soldering station and have a go at it. This is not rocket science either but lead to some burnt table tops, not to speak about fingers and other body parts.

 

Here is a great video about soldering magnet wires to SMD LEDs: https://www.youtube.com/watch?v=oW-IQ2-0jBg

 

This should get you started but let me know in case you are interested in other aspects!

 

Cheers,

Cristian

 

Edited August 18, 2018 by armored76

[busnproplinerfan]

Yes this is a bit of a new realm. Long ago, I rigged up a 1/48 B-29 with regular light bulbs and motors. Worked for a bit except I used props that were broken at one time and it threw a few blades. Made a 1/48 B-25 that had each engine start on a potentiometer (forgot how to spell it) and LEDs in all the right places. It worked good until the day of a model club display, then everything thing except the landing lights stopped working. Anyway, lots of blabbing. I did see awhile ago someone in the UK made a circuit board to fit in the wing of most 1/144 airliners, that guy disappeared.

I'm not sure where to start outside of looking at what you sent. Can these be set up to run with a tv remote or something similar? On the 1/48 models, I ran the wires through the landing gear disguised as a brake line through the axle and down the tyre into the base. How do 1/144 airliners hide the wires beside generator carts? Another thing is I'd likely use fiber optics for small tip lights.

[armored76]

You already have more under your belt build-wise then I do, then I only made a Warhammer Dunecrawler with LEDs so far and it didn't turn out that great, to be honest.

 

The setup is really only limited by the space you have in the model. I think most airliners offer generous space in the main body, tough.

 

For more complex things like synchronized blinking patterns and timed sequences you will a microcontroller, a very simple processor, if you will. This can deal with different inputs and can control different outputs. One example would be such a microcontroller hooked up with a Bluetooth module that controls an LED driver. With the right software (to be developed to your own requirements) ,this may allow the control of the model lights (and propellers if you'd like) from a smartphone. A TV remote is also doable but there are slight differences between remote makers which use different codes for the same key, surprisingly making this the more complex solution.

 

The best about all this is that a lot of modules are readily available. There are boards with microcontrollers for really low prices (~5 GBP), Bluetooth modules, LED drivers, etc which "only" need to be connected to each other. As for the software, there are also ready made pieces (libraries) and a huge user base to help you get started. As with everything, this needs some study and work at the beginning but so does everything in life

 

Here a few examples:

• my favourite microcontroller board is the Arduino Pro Micro but the AtTiny85 mentioned by Will above is a nice alternative, too and even smaller
• I don't have hands-on experience with it but, this seems to be a nice Bluetooth board: https://www.adafruit.com/product/1697
• these boards can drive 16 or 24 LEDs or LED groups: https://www.adafruit.com/product/1455 and https://www.adafruit.com/product/1429

Check the prices for all of the above on Ebay as the boards can be had for really cheap if imported from China.

 

There is sure a lot more under the hood but this should give you a first idea of what is possible. It might seem overwhelming but it's not that bad

 

Let me know in case you need extra details about any of the above!

Cristian

[busnproplinerfan]

I'll be looking at some of this as I go. I don't have a cell phone, but I guess a used junk one could serve as a controller. Wonder if one phone could do more than one plane. Might look better than having switches built into a diorama. Reading the descriptions on the components, it looks like they took the time to make the parts more user friendly. I'll have to start small obviuosly(pun intended to). Huge thanks for showing this. I also have  a1/72 TU-114 Cleat I want to set up to run with lights. I have an idea in my head for the counter rotating props. I guess engines could be controlled with this to?

[armored76]

Actually, infrared receivers can also be used instead of the Bluetooth ones without that much more overhead. In case you give each of your models a different address, you can control each model with a different group of keys on the same remote. It's all doable in software.

 

Have a look at this article for some great basics of the infrared communication: https://learn.sparkfun.com/tutorials/ir-communication

 

Concerning the motors, these can also be controlled the same way but in this case an external circuitry is a must if you want them controlled by a microcontroller as these can usually nly deliver around 20mA while even mini motors require around 60mA.

 

Here is a great article about controlling DC motors: https://learn.adafruit.com/adafruit-arduino-lesson-13-dc-motors/overview

 

In case you have a list of lights and motors you'd like to control, we can try and set up a project here, if you wish.

 

PS: Is the TU-114 the Welsh Models kit? It looks... daunting

Edited August 19, 2018 by armored76

[busnproplinerfan]

Those are interesting. I don't know if i would do more that one model, well would nice to be able to with one contoller of some type. The motors I would use are he little cell phone vibrator motors. If I do an airlier, I'd consider having the turbines spinning, yes that would be a bit of work in 1/144, might be better in something 1/72. Otherwise, the TU-114 would have eight motors in total working in pairs. The TU-114 I have is the A-model kit. This one, I'd want to start each engine(pair) indiviually and maybe have it start off slow and adjust the speed a bit. These will be geard down a little, depending on the space in the cowlings.

Edited August 20, 2018 by busnproplinerfan

[armored76]

Sounds like a great plan!

 

I guess the engine pairs will always run synchronously, at the same speed? If so, we could connect two of them in parallel to the same control channel and only use 4 channels for this.

 

How many lights (LEDs), if any are you planning to add?

Edited August 20, 2018 by armored76