When do we need to use a microcontrollers?

When do we need to use a microcontrollers?

When do we need to use a microcontrollers?

Hi, Guys,

This is a very long post which I hope I can help when you need to design your own lighting circuits.

When do we need to use microcontrollers?

The first thing we need to observe is, the lighting patterns of a model. Except for the Tydirium Shuttle, a simple LED or LEDs will help for most Star Wars spaceships. But if the model has a fixed lighting sequence, say, a landing strip with moving ‘dots’, then an off the shelf circuit will do. Or, if you have a Tower which needs and anti-collision lights, even a blinking LED can solve the problem.

But if a Spaceship calls for a Photo Torpedo or even some flashing Navigation lights, off the shelf circuits can still save the day. One great Bible would be the Starfleet Assembly Manual by Paul M. Newitt who has drawn out the complete electronic circuit for the 1/537 NCC-1701A.

So, when do we start to use the microcontroller?

My answer would be, ‘It depends‘.

If an off the shelf circuit can do the job, then I would go for that route. But in Scale models, off the shelf circuits tend to take up a lot of space even if you have the smaller SMD (Surface Mount Device) components. The microcontroller is usually seen by a lot of people as a ‘problem solver’ but in some cases, it also drives up cost. Sometimes, there is no point in getting a Cruise Ship for a fishing trip on a lake. I would start to look a microcontrollers when the lighting effects calls for:

1. Multiple Fading and Speed effects (The Starting of the NCC-1701A’s Deflector dish from copper orange glow to Blue.)

2. Different Light sequence. (Ghostbusters Proton Pack)

3. Synchronised Control of Servo motors or even Smoke Machines

4. Synchronised Control of Sound

5. Interactive responses. and so on.

Let me say this again, Microcontrollers are expensive and it is not just in terms of cost. The time and investment spend on learning how to program them, not forgetting the programming hardware. Then you would also need to choose if you need to learn the C language, Arduino or even Phython. The former will give you the end result in a single chip whereas the others comes with their own board. This can be a challenge if you need to customise your own circuit board unless you learn more about boot loaders, etc. Microcontrollers save space, power and needs minimal supporting components. Arduinos and Pi are more powerful but you’d need their whole board and also learn their language (no, really. You cannot just download sketches, then cut and paste with them). And I haven’t even talked about circuit board designing too.

Anyway, here are some examples from a simple component to a real microcontroller solution. Most of them are videos from my own YouTube channel and some are so old, even the original text (notations) are missing.

Random flicker LED

One good source of random flicker would be the tealight or candle LED. The latest version would be in the form of the 5mm LED in White colour. A single LED would look great for a small slow thruster but if you solder at least six, you would have a very nice thruster with an almost random flicker.

The YouTube video above shows how the 6 candle LEDs are used to create a nice thruster effect for the Hasegawa 1/20 Falke

Uniform Repeated Sequence

A very good solution for 10 LEDs and less which needs a simple straight sequence would be the 555/4017 circuit. The 4017 CMOS Decade Counter can be re-configured to sequence for less than 10 leds. ANd with some external diodes and components, it can also be configured to give a forward/reverse sweep ala Knight Rider but with only 6 LEDs (compared to eight from the show). The circuit, I believe, was used extensively in the Star Trek TNG shows especially on the Tricorders.

The YouTube video above how an off the shelf 555/4017 is used to give the illusion of a spinning propeller for the Hasegawa 1/20 FLKE

Police Siren Lights

Depending on the scale of the model, you can also use the same 555/4017 circuit to achieve the effect.

This video shows you how you can use the 555/4017 circuit to simulate a typical Police Flashing lights.

Uniform Blinking

A very good example would be a typical Starfleet Ship where the Red and Green Navigation lights and the White strobes must blink in unison. Not only that, the timing of the lights varies from ship to ship (OK, TV Series and Movies). A typical blinking LED comes to mind and they are available from 0805 SMD up to 5mm LED. But they have their own issues. So you connect them together and switch them on. After a few seconds, you will notice very quickly that all the LEDs are blinking ‘randomly’. A few seconds later, they are back to normal and the cycle repeats itself. Minute variations during manufacturing are what, I suppose, to be the cause. On the other hand, you can use blinking LEDs as source and connect them to a transistor to drive the other LEDs simultaneously. However, the problem is that these blinking LEDs are made to flash at 1.5Hz (0.667seconds) and you cannot control them. The microprocessor is housed within the LED itself.

This microcontroller prototype can be used to give you the solution of separate flash sequence of both Navigation and Strobe systems for four different Starships (Motion Picture Enterprise, Star Trek VI Enterprise, NX-01 and 2009 Enterprise).

Lighting Effects: Welding

One good example which pushes you to the microcontroller path is the simple welding effect. There are various off the shelf methods to achieve the effect but none of them could create the ‘ending fade’ of a weld or, even the inconsistent welding pattern where the welder pauses or has some delays. A simple microcontroller (with enough memory) is capable of achieving this.

A prototype where the micro controller simulates a welding effect for a figure. The first LED (left) is the welding point while the rest of the LEDs are supposedly the droppings of the molten bits (connected to fibre-optics). The first second is the normal background welding while at the push of the button, it switches to the main actor welding with more effects.

Lighting effects: Thrusters

I really had to use a microcontroller for this after seeing the thruster effects of the QMX model. The Episode ‘Dirty Hands’ mentions the effects of impurities in the Tylium fuel. So, this means the ore was manually refined and therefore, was never 100% pure. The end result would be some improper burning which give rise to the almost random effect on the thrusters.

The 2011/2 Prototype of the Viper Board which has two types of Engine flicker form the TOS to the nuBSG. The boards were sold out long ago but I might want to do another run in 2023 if the chip shortage issue is solved.
The Ad which we used to spice up interest

Microcontrollers can save space 01

Apart from using less power, the microcontroller can save space which is a premium in a scale model. Depending on the complexity of the lighting effects, there are always two main choices:

1. Putting the circuit board outside of the model allows you access to either repair, upgrade or modify your design. But at the cost of massive wiring into the model.

2. Putting the circuit board into the model solves the problem of wiring but you will definitely worry about potential heat generation, and Murphy’s Law. However, this would also mean bespoke circuit boards.

Looking at this video below, the circuit board is about 1.5 inches long and fits into the model. It has 10 SMD LEDs in there and is powered at 4.5volts. This took me weeks to solder all the boards for a few runs. The best part is that a single chip replaced a lot of components and allows me to custom design the board to fit into the model.

Microcontrollers can save space 02

Another example is the 1/24 Blade Runner Spinner from Aoshima. At the last count, I think there are about 40 plus LEDs in the model. The lighting effects is quite extensive and I had to use about three microcontrollers. The good thing is that they do effectively help me in reducing the component count and the cost.

A Video of the prototype cicuit for the Blade Runner Spinner before I confirmed the PCB design:
Posted in A Piscean Works Blog, Arduino, Artwork, Audio, Battlestar Galactica, Blade Runner, Computers, Design, Electronics, Flowcode, Ghostbusters, Hasegawa, JLCPCB, Lighting, Ma.k, Maschinen Krieger, Microchip PIC, Microcontroller, Model Kits, Modifications, Printed Circuit Board, Programming, Proton Pack, Scale Lighting, Scale Models, Sci-Fi, Spaceships, Spinner, Star Trek, Star Wars, Technology, Tricorder, Upgrade Parts, Video.

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