Notes on Magic Wand V4
Jan. 13th, 2015 11:28 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
carlfoxmartenWarning: 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. =^.^=
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. =^.^=
![[identity profile]](https://www.dreamwidth.org/img/silk/identity/openid.png){kind=small}
no subject
Date: 2015-02-03 11:01 am (UTC)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.
no subject
Date: 2015-02-03 07:53 pm (UTC)(fortunately the effect is becoming less pronounced with age)
Almost a year ago, I used to use one of Google's many services called Google Reader, you give it a list of RSS feeds and it assembled their updates into a date-sorted list.
Every day I would visit Google Reader to see what websites and webcomics had updated.
Unfortunately, some twit with power at Google decided it wasn't doing them any good and shut it down (fortunately with warning).
This sparked a bunch of other web services to either start up or branch into RSS feed reading, including Feedly, which is the service I use myself.
no subject
Date: 2015-02-03 08:48 pm (UTC)I have a huge issue with indecision that extends to many areas of my life, which, unfortunately, includes my fursona.
When I originally created the name “Carl Foxmarten”, I was merely trying to come up with a name I could use on the Gene Catlow forums.
‘Carl’ was a name similar to my real first name, close enough that I figured I could react to either, but I'd originally wanted to be Carl Fox.
Now, there is already somebody else calling themselves that, so it would have caused some confusion had I not read that foxes are by far the most common species to use when somebody first joins the furry community.
I'd recently listened to an audio version of Martin The Warrior by Brian Jacques, which featured a pine marten for the villain's right-hand-creature, who eventually left the villain's army due to realizing how evil he was, so I decided to be part pine marten as well.
That's about all I've got, really.
The reason I haven't added more up to this point is because I haven't given it any thought.
I'm also sort of afraid of adding any additional story because it might limit options in the future.
On the CTC forums, the character of Carl has a sort-of girlfriend in the form of a foxtaur named Meri.
She's from another planet (and universe, technically) and can wield healing magic.
(which was rather helpful, as, in that story, Carl was just about a danger magnet...)
no subject
Date: 2015-02-07 04:58 am (UTC)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: http://en.wikifur.com/wiki/List_of_most_popular_species
no subject
Date: 2015-02-07 11:49 am (UTC)Since I don't have any confidence in my writing ability as yet, I'm currently sort of avoiding pinning Carl down too much.
What I do have thus far is what I've written in past entries, plus the fact that he hangs around the CTC, even having his own workshop there.
(I wrote a short story about a morning in his life there, and you can find it here. Note that anything after that happens after the big long collaborative story I was involved with, so characters, places and things are left unexplained)
A few things I feel are important to his character:
- Very technically-inclined.
- Has invented several things that inhabit my dreams, including a hover-scooter, holographic displays, highly compact supercomputers, AI helpers, etc. Not all are fully fleshed out ideas, as they weren't in any way important to the stories I've dealt with before now.
- Because my life is the only one I have full access to (gee, I wonder why?... =^.~= ), I have sort of patterned his personality and situation both after mine and what I would like to have as mine. For example, quiet and reserved, very geeky, few geographically-close friends, lots online, plenty of money to use for the many and various projects he works on, some of which are not quite possible now, but are covered rather thoroughly by several different science fiction series.
That's about all I've got at the moment.Very little history at present, and nothing about his parents or siblings as yet.
He does have a girlfriend at the moment, as I think I've mentioned already, though I'm not entirely sure of all the deatils on that, including who owns the character and what her other characteristics are like, despite having the thickest Scottish-type accent I've ever had to write...