carlfoxmarten: (default)
[personal profile] carlfoxmarten
Warning: Gets very technical, so beware!

So, the very first magic wand the theatre company I'm involved with had caused some electrical burns to its original operator due to malpractices by the original creator.
I think it might be fortunate that he's dead now, though I think it was more due to age than an accident with his contraptions.

The second version (that I'm aware of) was the one that our current fairy queen broke this year taking last year's decorations off it, so the third version was the one I fixed up and improved.

The fourth version, which this post is about, is one I've been asked to build to replace our old one.
The fifth version, and there will be one, will have even more features than V4, so we'll either be able to choose which features to enable, or which wand to use for each year after, depending on what features we want to use that year.

First off, the old wand (probably version 3) could only glow when on and charged (via a white LED in the middle of the bulb) and flash brightly (due to a cut-down flash unit inside the wand's bulb). The goal of this project is to add extra features to it so we have more flexibility with regards to how our fairy looks.

The one thing that definitely will not change is the brilliant flash, and it will still be done with a flashtube connected to a capacitor and flash unit taken from an old film camera.
The nice thing about the board I found is that all the wires are marked! =^.^=
Which is a good thing, because the board itself combines newer (at the time) surface-mounted components with regular (not sure what they're called) components, so there are parts on both sides of the board, all very tightly packed together, which would make it almost impossible to figure out what the circuit diagram is! =0.o=

The first feature that I'll be adding for sure is an RGB LED and an extra button.
This will allow the fairy using it to have it do something interesting when she's invoking a spell.
For instance, the LED can change colours smoothly when the secondary button is pressed, or it could gently pulse from black to this year's chosen colour, or even cycle through a range of colours.

This means that we'll need a small microcontroller to control it, and there are few microcontrollers smaller than the Adafruit Trinket.
The Trinket is based on the Atmel ATtiny85 microcontroller chip, which has a mere eight pins, five of which are for I/O use, and has a very low current draw of about 15 milliamps.

Three of the I/O pins on the Trinket are capable of Pulse-Width Modulation (PWM for short), which means that they can effectively control the brightness of LEDs (at least to human eyes) by rapidly turning them off and on at specific frequencies and duty cycles.
All three of those pins will be used to control the RGB LED, which is made of three smaller LEDs inside, one each of red, green, and blue.
This allows the RGB LED to create almost any colour we want, which will allow us a great deal of flexibility.

The one concern I have is what will happen when the capacitor is being charged by the flash circuit.

On my test bench, I've hooked up an LED across the power wires to the circuit board (with the appropriate limiting resistor), and it completely goes out when the capacitor is being charged.
This means that the charge circuit is almost literally sucking power from the batteries and there won't be any left for the microcontroller or LED while it's charging.

Fortunately, it only takes about four seconds for the charger to ramp the capacitor up enough for it to stop taking quite that much power from the batteries.
Theoretically, after those four seconds, there ought to be enough power left over for the microcontroller to boot back up after getting essentially power-starved.
I'll just have to make sure that it comes back up in a way that isn't visually distracting, otherwise I may have to have two separate battery systems! =0.o=

As for the wand's construction, the old one had a pipe for the handle that is large enough to fit AA batteries in (of which it uses three), holes drilled and cut for a power switch and a trigger button, and had four wires (two for power, two for the button) running up the wand's shaft, so all were (relatively) low-power wires.

Unfortunately, this meant that all the important guts were in the bulb at the wand's tip, which in turn meant that there was a limit on how large things could get inside there.
After all, they couldn't interfere with the flashtube's light...

This time around, my goal is to make it as slim as possible up at the tip, so all the electronics are not stuffed into a small space.
Instead, I want to put just the flashtube and LED up there, with all seven wires trailing down the shaft to the various circuit boards situated in part of the handle.

Because there will (or should) be so little in the tip of the wand, I can house them inside a short length of clear tubing, and then we can change out the shape on the wand's tip as a part of the fairy's outfit each year.
For example, we'd finally be able to use a star for the wand's tip! =^.^=
(I do have other ideas for stuff to put at the end of the wand, and yes I've been writing them down)

Anyway, the four wires for the LED are going to be fairly straightforward to deal with, but it's the three wires for the flashtube that's going to cause me problems.
For one thing, two of them are going to be dealing with about 500 volts, and the third wire is going to get spikes of 2,000 volts every time the trigger button is pressed, so I need to use some sort of high-voltage wire, but I'm not sure where to find some around here.

Actual physical construction of the wand is somewhat tricky to describe using text alone, but if I don't try I won't figure out how to do it for next time.

Starting from the tip of the wand, there's a clear plastic tube that contains the flashtube and RGB LED, which leads down to a (preferably) metal tube for the shaft (as it's about four feet long, plastic is far too flexible for how slim we want this part), which is then connected to a plastic cap that screws inside the end of the handle.
The handle itself is at least a foot long (exact length will be determined based on the amount of stuff that needs to fit inside it), and contains two separate sections, the “bottom” end of which is a plastic tube large enough to contain three AA batteries, is mostly cut-away on the side so the batteries are both held in and easy to remove, and has metal contacts to get the batteries’ power to the rest of the wand.
The “top” section is another section of the same size tube as above, but is firmly attached to the cap the shaft is attached to, and contains all the circuitry necessary for the operation of the wand.

It will be necessary to have a connector or something between the handle and battery compartment, and the shaft-section of the wand, but hopefully I can handle it without too much difficulty.

The reason for having all the components inside the handle, and in a different section of the wand from everything else, is for safety's sake.
We are talking about high voltage electricity here, and if somebody merely replacing the batteries could accidentally touch some wires that contained dangerous levels of power, they could either be badly hurt, or even killed, which is something that only technicians repairing the wand should have to worry about.

Once it gets right down to it, though, probably the hardest part is teaching a fairy to use it.
Yes, it has two buttons, but you have to be able to press them easily, and without moving your hand between them! =0.0=

I'm also hoping to get this built by February 27th, as that's when the theatre company is having a potluck dinner for all the cast and crew (and whoever else is interested in showing up).
That way I can show it off. =^.^=

Date: 2015-01-14 03:59 pm (UTC)
From: [identity profile]
Hoping for a photo or two of the wand as you build it please :)

Date: 2015-01-16 02:05 am (UTC)
From: [identity profile]
When (eventually) I commission a fursuit of Sebastian I'll be wise to consult you about the electronics for the LEDs.

Date: 2015-01-16 07:30 am (UTC)
From: [identity profile]
No hard blinking, as I will need to extend the life of the LEDs as much as possible, but I'll want the colours to softly shift in very specific patterns. The idea is to simulate the colour-changing abilities of a chameleon (Sebastian is a wallaby-chameleon hybrid: . I'd like to have a control built somewhere in the suit that allows me to dial up a specific colour, or choose a mode of gradual colour movements across his body.

It's all in the theoretical stage at this point. This suit is going to end up being painfully expensive.

Date: 2015-01-16 10:36 am (UTC)
From: [identity profile]
*Very* theoretical at this stage. The huge wad of cash needed to make this happen will not be until at least a couple of years after I dig into my savings to fit an air-conditioner into this 10th floor foxaroo-roasting trap of an apartment (I only had 3 hours sleep last night thanks to the temperatures).

Firstly thanks for the info on LED life. It might be an idea to have a sensor built into the circut to have less power used when there's less light - the darker the ambient light the more easy the LEDs would be to see.

A huge lot of LEDs yes, but not excessive. Just enough to make the idea of a chameleonic fursuit work. My idea is that it will also incorporate having large metalic sequins decorating the suit, arranged to look like scales.

At this stage I'm only planning to have LEDs on the front of the body - that way it encourages people to come in front of me where I can see them. No leds on the head or legs either. And I'd prefer to keep the design simple and easy to maintain. It has to be folded away neatly when not in use, so I want to avoid anything that breaks easily. Also I'd prefer controls easy to operate from within the suit, keeping in mind both reduced visibility and dexterity. I was thinking of a notched(?) dial, though possibly with the option of settings that can be programmed before I put on the suit.

Everything would also need to be waterproofed for safety. I'm certainly not planning on taking a swim in the suit, but I do sweat profusely.

Date: 2015-01-17 06:31 am (UTC)
From: [identity profile]
Had already started a thread on the Furstralia forum: but you can only view it if logged in. I haven't been active on Furstralia though since the day I was made redundant. It's been one of life's bitter twists. Now that I'm employed again I'd very much like to be back there but my new job is even more demanding than my last one.

The conductive thread sounds good, so long as its durable. Doesn't matter to me though if the LEDs are visible, and I'd like them to be large enough to give off a decent glow.

A waterproof layer is what I had in mind. The suit will already need this because I aimed to do what one of the other FurJam fursuiters already has and incorporate a couple of inward pockets to hold frozen gel packs to help keep me cool when needed. Will need some insulation to keep moisture from forming anywhere near the electricals. I'd be OK with resin, so long as replacing burned-out LEDs doesn't become impossible.

As to the actual design for the circuitry, it's probably too soon to speculate on how that's going to work. To quote an old BBC documentary narrator - These questions are for the future.

Date: 2015-01-17 12:09 pm (UTC)
From: [identity profile]
Re the Furstralia forum, the problems began a few years ago with the mass exodus of Aussie furs to Facebook. The then owner of the forum figured that PhpBB was out of date and announced that replacing it with something called "Vanilla" which had "lots of new features" would attract everyone back. It turned out to be the most awful forum in appearance, and did not provide even one new feature. Not one. He later claimed that the real reason for the change was because the forum had been hacked at some past point. Then the owner decided to call it quits and asked if anyone wanted to take it over, which thankfully one furry in Queensland did. He's been working hard to restore it from the mess that it ended up, but there's a lot of stuff that he's still trying to synch back to normal. Duplicate posts are just one of the symptoms - I ended up with the avatar of someone I don't like and he accused me of trying to steal it from him.

Re Sebastian. He has a mixture of both; scales with fur growing out between them. Both his scales AND his fur can change colour. However the technology to make this possible in a fursuit isn't going to exist within my lifetime. I'll have to make do with what's available (assuming I live long enough to be able to afford this).

No, it's not a case of "Look at me! I’m lit with LEDs!" or even "Hey! My suit changes colour!" It's a case of "This represents Sebastian's chameleonic abilities." If affordable technology existed to create a fully chameleonic suit I'd be going for it.

Making the LEDs less obvious would suit me, so long as ease of maintenance is preserved. I don't want to be hacking pieces out of the suit whenever it becomes necessary to replace blown LEDs.

Re a fan in the head, I wouldn't allow it to be made without one. I was very disgruntled with the design of my foxaroo costume because I expressly requested TWO fans in the head, with holes below the ears to act as exhaust ports. However the costumer created no holes at all, and simply stuck in a fan to (supposedly) circulate the air inside the head. It's only about 5% effective. Even with the fan running I still end up coming out of it looking like I've been dunked in a swimming pool. With a full-body suit intended for Sebastian I'm going to need every possible method of keeping cool. My warm blood is genetically coded for a cold climate, and isn't going to cope very well sheathed inside a full body suit in the Australian climate. Had I been able to emigrate to Canada it may have been a very different story.

Date: 2015-01-21 11:25 am (UTC)
From: [identity profile]
The Vanilla forums sure was horrible ("Was" or "were"?). The forum needed some spice and instead it got poison. I have no idea what the original forum owner was thinking.

I'm clicking on the links for Curtailed, but it keeps taking me back to the home page. Is the webcomic no longer viewable?

Re the LED brightness, yes that's where I think a light-sensor to balance the brightness against the ambient light would be a good idea. It might also extend the life of the LEDs.

Having canals in Sebastian's ears would be a good idea, as his ears are more rabbit-like than Michael's floppy ears. Michael's ears would have concealed vents quite well. No such option with Sebastian. The only question is whether pumping air through tubes would strain the fans?

Date: 2015-01-23 08:00 pm (UTC)
From: [identity profile]
Thanks. I like the look of Curtalied. The characters are comfortably drawn with good expressions and I like the humour. It's getting difficult to find good webcomics now - from what I can see many online cartoonists have gone over to pay-for-view.

Automatic brightness control is going to be pretty much essential for LEDs on Sebastian, as the only way I'd be able to gauge the brightness myself would be to take the head off and look in a mirror. It would take some tweaking and the assistance of an observer to get it to work. My apartment has light dimmers in the lounge room, which would be helpful in testing.

Having canals in Sebastian's ears would be a good idea, as his ears are more rabbit-like than Michael's floppy ears. Putting tubing inside the ears would strengthen them and help them stand up, though for cuteness I'd like them to flop around a little. What I was referring to in the comparrison between a Sebastian fursuit head and that of Michael is that for Michael the exhaust air could have been vented directly though holes cut right on the surface of the head concealed by the floppy ears. For Sebastian canals are going to be necessary, however there *will* be some degree of efficiency loss in the air circulation due to pulling the air through the tube. Those little fans aren't very powerful, and I would expect that there wouldn't be fans as small as the diameter of the canal tubing.

Date: 2015-02-02 09:25 am (UTC)
From: [identity profile]
If you have any good webcomics to suggest I'm all ears. Generally what I like are those with exquisite artwork, well-developed characters and intriguing storylines. Though these are not hard-and-fast rules. Dan & Mab's Furry Adventure fits all those, and yet I could never get into it. I've no idea why. Meanwhile the Alex Cartoon doesn't really fit into any of those either, and yet I've followed it enthusiastically.

Yes you're right about the sensor - finding the right location is going to be very tricky. So too is deciding where to position vents.

Date: 2015-02-03 11:01 am (UTC)
From: [identity profile]
I developed my assessment of what I like in webcomics during a conversation with Old Wolf when we were passing through Wolstonecraft station. Since then I've tried numerous times to quantify my tastes in webcomics more precisely and haven't yet been able to. It's generally the artwork, the characters and the story for me, yet neither have I been able to work out why there are exceptions to the rule.

Yeah, I'm the same with "fish out of water" jokes and characters - they do nothing but irk me. Americans (USA Americans) seem obsessed by the theme, although thankfully they're falling out of fashion.

Q: How do you use an RSS feed?

Out of curiosity, do you have any stories in mind about your fursona, or any background concerning him? Now that you have a visual version it would be nice to learn more about him.

Date: 2015-02-07 04:58 am (UTC)
From: [identity profile]
[ profile] carlfoxmarten said:"You want me to make decisions about my fursona? =0.o="

No. :P

I was just curious. There are as many different reasons for anyone having a fursona as there are different types of personalities.

For many people their fursona is nothing but an anonymity mask for the internet. Others, like myself, take their fursona very seriously and create detailed backstories for them.

Some people never develop their fursona, others swap and change their fursonas like new hats, while still others cautiously make improvements to their fursona over time. In my case Michael was originally a kangaroo until I thought of the hybrid idea some time in the early 90's.

Some concentrate only on the visual aspects, while others (like me) have little or no art skill and instead focus on the fursona's personality or stories/backstory. Snackish, the artist who produced my first image of GG1's anthro horse form and is currently working on something new for me, is a phenomenally talented artist and yet has expressed frustation at being unable to produce stories around her fursona. She has a rough idea about her fursona's species, but no idea what to do with her/them. I've offered to assist, and she was keen at the time but nothing has come about yet.

I liked reading about the history of how you created your fursona. It's very interesting. I've always liked the idea of your fursona being part pine-marten too My fursonas (believe it or not) started long, long before the internet. I'd always wanted to have a cartoon character of my own, and that's where Michael came from. Sebastian I've often suspected originated as a childhood imaginary friend... which is probably why he's so immature. ;) It's somewhat ironic that when I first started posting on forums I had no idea what a fursona actually was.

BTW A few years ago wolves overtook foxes as the most popular species in the fandom:

Date: 2015-01-23 08:32 pm (UTC)
From: [identity profile]
Oh yeah! :D

Date: 2015-01-21 11:18 am (UTC)
From: [identity profile]
Controlling each individual LED woudn't strictly be necessary as I'm not looking to create precise patterns on Sebastian, just slowly shifting patterns moving across his body, like the movement of clouds or ocean waves. That kind of thing.

Those RGB LED strips do look good though, and you're right; they solve a lot of problems right away, particularly the waterproofing. Programming several strips to work in conjunction though could be quite a feat, and I'd need to know how flexible they are - IE how far do they bend without breaking when I need to fold the suit away for storage & travel.

Yes, your estimation of the positioning of LED across Sebastian's front is pretty much spot on. He has the rotund lower-half of a wallaby, so that increases the surface area considerably.

Date: 2015-01-23 08:04 pm (UTC)
From: [identity profile]
That's why I'm *defnitely* going to involve you if I embark on this project.

Don't hold your breath though. Getting an air-conditioner for this appartment has to come first. Also, if I dish out thousands on this fursuit then it will be longer before I can make a return visit to Canada.

Date: 2015-02-02 09:14 am (UTC)
From: [identity profile]
Yes and no. The components and the suit itself can travel between here and Vancouver for much less than I can.

Or failing that, just your advice would be invaluable when the time comes.

Date: 2015-02-07 05:13 am (UTC)
From: [identity profile]
There's a gentleman whom I meet up with each Furjam who is very keen to help me with advice on starting a Sebastian costume if I get around to it. There's an Australian Fursuiter's website, and there are a few individual people here with enough talent to make what I need in Sebastian (they're not easy to find though, and often booked-up). I wouldn't have been opposed to ordering my suit from a more professional fursuit-maker in the USA, except that the Aussie dollar has fallen below 77cUSA.

However the electronics is a whole different ball game. I've seen a few fursuits that incorporate LEDs, but nowhere near on the scale that I'll be requiring.

(Having had very little sleep last night due to insomnia I'm going cross-eyed viewing the Mini Maker and Hackerspace websites).

All stuff for the future anyway. Plan #1 is to get an air-conditioner.

BTW - On a sour note Qantas was recently offering a good deal - AUD$2,000 return to visit Vancouver. Unfortunately I've already allocated all my leave time for the 2014/2015 year.


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Carl Foxmarten

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