hi all..I have engineered a homemade lightsaber. And im trying to develop a dc circuit that will create a pulsing effect in the LED to create the "glow/alive effect" of the sabers in the movie. Keeping in mind a long term project goal of adding in a clash sensor and sound device that works congruently and possibly a second "bright flash" LED. I am a nuclear navy trained Electronics sailor with 20 years experience. I have most of the theory down, but atm am completely oblivious to the design tools available to aid me in the process. Thanks for advance for any help you can give and ... ahem.. May the force be with you!! 8)

 

and.. obtw.. all the parts would have to be small enough that once put together fit in a flashlight hilt... if that wasnt obvious 8).

 

The smallest, and simplest (once you get into it a little), is a microcontroller. One 8 pin chip, and a driver (transistor/FET), and you can program most any effect, the chip will hold several, and handles sensors just as well. It would be ideal to your project, small and battery friendly, and can do a lot more than individual circuits, for each function or effect.

I know it sounds a little intimidating, maybe like it's more than you need or can handle. But it's not that bad at all. I started about two years ago, and these things are awesome, and dirt cheap. The 8 pin chip I use the most, Attiny13 is 83 cents each (quantity of 25). The software is free, compilers are free, and there are several cheap and easy to build programmers, also some ready built for under $20. The best part though, is you are working with LEDs. The very first project, regardless of which company you go with (PIC from Microchip is quite popular, although I can't understand why... ), is simple blink an LED on and off. Only takes a minute or two, and within 30 minutes you'll have that LED doing effects. Me second project was a chaser. Anyway, it's quite affordable, fairly easy to learn, and there are hundreds of websites with projects and support forums to help you.

 

One of the first things you'll need to do is decide how many and what color leds you want. Then decide what flash pattern. From there we can help you design the circuit.

 

Hello Sailor

Thank You for your Service to Navy and Country.

Yep, microcontrollers are the way to go. Amazing what you can do with a six- or eight- legged critter. I have a Microchip PICkit 1 programmer sitting next to me with a PIC12F675 flashing a dozen red Charlieplexed LEDs in random patterns.
Microchip: http://www.microchip.com/
Charlieplexing: http://www.google.com/search?hl=en&q=Charlieplexing

For driving the Luxeon LED(s), you could use something like an IRLZ14, IRLZ24, IRLZ34, or IRLZ44 which are all logic-level gate power MOSFETs of various current carrying capability. The IRLZ14's can carry up to 10A with a Rds(on) of 0.2 Ohms. The IRLZ44's can carry up to 50A with a Rds(on) of 0.028 Ohms.

Instead of a microcontroller, you could use a couple of SE/NE/LM555 timers (or a 556 dual timer) to build a PWM controller that would slowly increase/decrease the intensity of the LED. It would be cheaper to do it that way.

 

man you guys rock thanks for the quick help... ill be more specific about the situation. I have some links to stuff other people have done and i spose i could jusr RE their stuff but frankly its highly priced and i feel i have the brains to do my own. SO for now ill leave them out. If someone is really interested in the links ill gladly post them. I just dont want to feel like im "stealing" from someone else if that even makes sense.
In any case...The Leds are LUXEON IIIs and V's

for the V's i use a 7.2v 600a Li-Ion battery with a voltage dropping resister inline to bring the voltage to optimum across the diode.

for the III's its the same setup only I use a 3.7v 1400mah Li-Ion Battery

part 1
the general idea is random pulsating effect on the LED...with a ramp up and a ramp down on start and stop

part 2
sound - would be a constant hum with a swing sensor to generate the wooshing saber sound...and a clash sensor for the hit sound

thats basically it... im not really ovewhelmed by any recommendation.. and i prefer to go neck deep honestly 8).... so im all ears fellas.. 8)

part 3
2nd Luxeon (white) to flash only when clash is on.. to create the bright flash when sabers hit each other or other things...the poblem with doing this now is frankly the LED's come the size of a quarter.. which fight nicely into the blades hilt .. trying to figure out how to get two LED's on one heatsink and still fit them into the hilt is the challenge... there are led lines/bars i have seen i considered building/buying one of those and putting it into the blade for the flash as well...prolly will be most likley since i cannot see how to get two luxeons the size of a quarter onto a heatsink and both into the hilt and emitting up the blade.

 

http://picasaweb.google.com/dlooshnl/MyPictures/photo#5237452725157558178
heres a picture (if i can get the link to work) of what i have built so far thought it would help add some credability 8).. and possibly insight some ravenously helpful information 8)

 

Got a nice Maggie's Drawers on the pic there... unless your light saber looks like a red "x"

Sure, post the links to the other projects. Never hurts to see what others have done.

 

lol use the link.. i can never get direct picture links to work...

 

well one guy i have spoen to through email quite a bit about the lightsabers construction is Greytale.. he has a site on you tube at
http://www.youtube.com/user/greytale

he promotes and helped to develop this board
http://www.plecterlabs.com/Media/Doc/CrystalFocusSaberCoreV4.0-GB.pdf
which is waaay above and beyond what i feel necessary... but it shows the size requirements well and gives the hypercrazy idea of how far this can be taken..

greytale is a cool dood though.. ill email him and let him know we are talking bad about him hehe

 

so sgt wookie, what it seems you are saying is to use a mosfet to drive the LED.. and microcontroller that is programmed to adjust the gate to the mosfet such that the LED pulses? do i get you right?

if so let me ask this simply... if you were me... what would you do to learn about microcontrollers...im a pretty quick study...i perused the microcontroller website a bit.. it is a bit overwhelming cause there is soo much there.. i need to break it down a bit and work my way up hehe. it seems there are "practice" kits or something on there but im really not sure... im fine with investing time and money to figure it out.. just dont want to spin wheels in circles i spose 8).. thanks again

 

so sgt wookie, what it seems you are saying is to use a mosfet to drive the LED.. and microcontroller that is programmed to adjust the gate to the mosfet such that the LED pulses? do i get you right?

if so let me ask this simply... if you were me... what would you do to learn about microcontrollers...im a pretty quick study...i perused the microcontroller website a bit.. it is a bit overwhelming cause there is soo much there.. i need to break it down a bit and work my way up hehe. it seems there are "practice" kits or something on there but im really not sure... im fine with investing time and money to figure it out.. just dont want to spin wheels in circles i spose 8).. thanks again

I guess the first step would be to choose a manufacturer, you have several choices. For this project, the device choice won't make a huge difference, they will all handle the task well. You will most likely want to base you choice on programming language. If you've done any computer programming, its pretty much the same, and there are compilers available for several languages. PIC is by far the most widely used by hobbyists, but there are a few things that I didn't care for. I risk starting a war here, just hope everyone plays nice and sticks to the topic... I was most familiar with Assembly, and PIC has only 32 instructions/ one register, so expected a lot of redundant MOVE, LOAD, and STORE type instructions. No big deal if you use a high level language like 'C' or BASIC. Most PIC software seemed to be purchase only, didn't read much about decent free compilers at the time, maybe it has changed, same with software for the programmer itself. I didn't want to spend several hundreds of dollars trying to find something I was comfortable with, or many months getting use to programs with a steep learning curve, plus learning the chip, its features, and the associated software. For you, PIC might be good, you have dozen of people here already to point you to what's best, and what to avoid.

I chose the Atmel AVR microcontroller, 130 instructions/ 32 registers. Programmer software is free, as well as several choices in compilers for different languages.

Anyway, a development board or evaluation kit might be a good choice, usually comes with everything you need to get started. But doubt they have any for the smaller chips, and you really don't need the biggest and baddest for this project. You might check into PICAXE, it runs BASIC, and the beginner kit comes with everything, not too expensive either. Remeber a few posts about it, but never that curious, but should be good enough for your project, and quick and easy to get started with.

 

We use a EasyPic4 and 5.($129) It's a complete developement board that'll program from 8 pin to 40 pin controllers. http://www.mikroe.com/en/tools/easypic5/
You can download the software for free if you want to try your hand at programming. they have a free online book/manual for programming plus online web forum to post questions. We use mikrobasic language. In the programming software they have sample programs for various pics that you can modify to fit your needs. I'm not saying this is the best stuff to get as I am very inexperienced with this, only used it for 8-10 months, but we like it.
For your application it may be more money than you want to spend, but I gotta tell you ,it's addictive. Two of my students bought thier own programmers for home use, they couldn't get enough of it in class.

 

Well, you can get started for $35 with Microchip's PICkit 1, but it's rather limited.
That EasyPic5 is mighty impressive; lots of possibilities for interface. Looks like it would support most of Microchip's PICs in DIP form. Quite a "busy box" I'm rather tempted to get one myself.

Note that mikro has a number of compilers that are available for free download. They're fully functional, but limited to 2k of hex code. In the case of a PIC12F675, they only have 1k x 14 (1024 14-bit words) of program space anyway.

They even have a version of Basic. Have to be careful about using multiplication and divison though; they'll cause your code to bloat and slow to a crawl.

As far as Microchip's offerrings, the PICkit 1 isn't a bad starter kit. However, it's limited to just the 8 and 14 pin devices. The PICkit 2 can program quite a few more PICs, but you generally need to have them in a board first.

The EasyPic5 appears to get you up and going right away, with a very feature-rich development board.

The only possible complaint I could have with it, is that it's not capable of production programming specifications - but neither are the PICkit 1 or PICkit 2. In order to get that capability from Microchip, you'd need to fork over the better part of a grand - and you would have to pay extra for a decent dev board.

I do like the relatively new PIC16F887's - I have a few that just arrived last week. Remarkable features/performance for the price; and they even have an internal oscillator.

For your current project, such an IC would be maximum overkill. However, it's great to plan for the future, and get something that's capable of handling a wide variety of uC's

 

so the easypic5 is the one your saying will allow me to start out slow and grow into as well? or did i misunderstand? im fine with spending a couple hundred dollars to get a system capable of growth if there is such a thing and at the same time allow me to start out and not be completely overwhelmed... i sat down and wrote up all the controls i would want as follows to make sure we are on the same page ..some are longer term goals admittedly but one system that could be used to work all the angles would be AWESOME 8)

-LED controller to Pulsate (flicker like a candle) the light
-clash sensor that generates a sound and drives a second white LED on clash
-motion sensor that generates a constant internal hum and wooshes when it detects motion (2 sounds a quick woosh and a long woosh)
-internal motor (like a cell phone vibrator) the is always on
-power up - sound and voltage ramp up
-power down - sound and voltage ramp down

 

so the easypic5 is the one your saying will allow me to start out slow and grow into as well? or did i misunderstand?

I think that it is a combination of a highly versatile development board, along with being compatible with the majority of Microchip's PIC line of uC's (microcontrollers)

Im fine with spending a couple hundred dollars to get a system capable of growth if there is such a thing and at the same time allow me to start out and not be completely overwhelmed...

Well, there will certainly be a learning curve. However, you've BTDT, and can DIT (do it again) It's structured, but a very flexible and it seems to me, a sensible structure.

I sat down and wrote up all the controls i would want as follows to make sure we are on the same page ..some are longer term goals admittedly but one system that could be used to work all the angles would be AWESOME 8)

-LED controller to Pulsate (flicker like a candle) the light

There is a whole field of LEDs on the board to play with; that can display activity of any pin of a PIC.

-clash sensor that generates a sound and drives a second white LED on clash

That would involve an on-board LED and an off-board sound amplifier.

-motion sensor that generates a constant internal hum and wooshes when it detects motion (2 sounds a quick woosh and a long woosh)

Out of necessity, the motion sensor would have to be located off the board. However, it might be simulated on the board. There are remarkable 2d and 3d motion sensors available which would be suitable for your application.

-internal motor (like a cell phone vibrator) the is always on

Well, that's not really necessary on a development board. Just leaving a pin open to drive it will work.

-power up - sound and voltage ramp up

There are no provisions for sound on the dev board. However, you could pipe sound/PWM to external circuits to drive a speaker/headphones.

-power down - sound and voltage ramp down

Same as above.

 

I finally got my easypic5 board from overseas...thanks for all the advice. Now i just need to figure out a "best course" of action to become familiarized with what this thing is capable of.... are there any recommended tutorials you guys can link. They have one very basic program in the BASIC code style that makes an LED blink. As far as BASIC goes I am very familiar with macroing and the BASIC code style is familiar enough to me that I can muddle through it with the references they provide on the mikro site. I was just wondering if you guys know any good "famaliarization projects" i can get links to.
Thanks again for all the help

 

It probably came with a '887 controller , so now you get to play with the 'sample programs'.

C:\Program Files\Mikroelektronika\mikroBasic\Examples\EasyPIC5 mikroBasic examples (P16F887)

Here is the default path where you can find the samples.Start out with the led program and change the time and port values to make it do different things. See if the changes you make do what you think it will.

 

lol, dang i shoulda noticed those, I'll play with them thanks Gerty

 

Another thing, you'll need to read and understand the data sheet in order to see what's going on in the pic.

:http://ww1.microchip.com/downloads/en/DeviceDoc/41291E.pdf

You can download datasheets from microchip for all thier pics