Three button RGB saber advice

[obiwanwasabi]

Hi all

Sorry to do this, but my four-year old son Luc is threatening to disown me if I don't work this out.

He already has quite a collection of Hasbro sabers, but a while ago he saw a kid with a custom job. It was pretty basic - more or less a plain black hilt with a few grooves - but was caught his eye was the three buttons controlling an RGB led. Naturally, this led to a request for a new saber. Not having the faintest idea where to start, I hit Google, which led here, and I've spent more time than my wife and employer would like reading page after page of posts. I've gone back to Luc with a plan, but no dice.

"Here - we'll make this PVC hilt, and I'll pop in this TCSS led kit and TCSS blade holder and blade. What colour would you like?"
"Red, green and blue."
"No, you can only have one colour. How about green? Green is awesome!"
"No, it has to be black and have three buttons and make the blade red, green and blue."

*sigh*

So, back to the forums, reading everything I could that came up on a search for 'rgb*'. I'm starting to go in circles, so thought it was time to put my neck on the line (tends to be arms and hands with sabers, though) and ask for advice. I'll try my hardest to be clear and concise about what I'm looking for, and to give links to stuff I've read already.

What I'm trying to do

I'm trying to make saber that fires an RGB led with a button for each die. That's it. No sound, no driver, no sensors, no recharge unit, no secondary leds, no illuminated buttons, no automatic colour changing, no colour mixing beyond what can be done with three buttons. Given that this is a kid's toy and that I'm probably going to end up having to make four of them, I'd like to do it cheaply.

What I've learned so far

The RGB posts on the forum seem to mainly discuss wiring up leds with driver and sound boards, or using something other than buttons to control the led (eg pots, rotaries, dip switches), or both.

The closest I've found is Matt Thorn's three switch RGB saber. Looking through Matt's posts among the various RGB threads, I came across this thread from Matt, in which he discusses wiring up an RGB led to some sort of switch to drive a Force FX conversion. As with many other RGB posts, there's a lot of (totally awesome) stuff going on in those diagrams I don't need, but I thought they'd be a good place to start for my first stab (ha) at a wiring diagram. Put on your noob deflection goggles...now.



It should be abundantly clear by now that I'm an economist, Jim, not an electrician (god, I can't even keep switch acronyms straight in my head - PSTP?!). I freely admit to having no real idea how the negative wiring on the LED works - I've just lifted it straight from Matt Thorn's diagrams, and adjusted it because I'm not using the amber LED. (Why no negative for the blue or red? *shrug* It was like that when I stole it.) I was also planning on lifting his resistor values, but decided against it because (a) he's using a board between the battery pack and the LED, and I'm not sure how that mucks things up and (b) I'm becoming convinced that before I trash a $35 LED I should start with something less valuable from That Place That Cannot Be Named But You Know What I'm Talking About (TPTCBNBYKWITA), and the different wattages would be a gamechanger.

What I'm hoping to learn

Does this look even remotely right? If it's not even close, please feel free to say so and I'll go back to researching so I can make less of an idiot of myself next time.

If it's close, though, or even ballparkish, I'd really love some advice about how to fix it. Apart from incorrect wiring connections, I'd appreciate anything you could say about resistor values for a cheap LED from TPTCBNBYKWITA. If it helps, these appear to be the relevant values for calculating the necessary resistance.

Thanks so much for your time and previous posts, especially Matt - I'll stop stalking you for a while now.

Cheers
obiwanwasabi in Canberra, Australia

[Azmaria Dei]

ok, i actually read through that and didn't lose interest, so good job on making a non-noobish new person post. ^_^ and welcome to the hobby. it can get expensive, but sticking to PVC should help mitigate those costs. Darth Midian and others have made some really awesome sabers out of it and there are some great tutorials/build logs here on them.

first off, to help keep costs down, i recommend using the dealextreme RGB that can not be linked here out of respect to Tim (you should be able to find it fairly easily though). shipping takes a long time since they literally come from china on a slow boat, but they're cheap and have great coloration. no matter what LED you use, be sure to use a heat sink (those that work with PVC can chime in about that later). CREE is also a good RGB LED maker and i personally like their star mounts better since all the LED pos are on one side and the LED neg is all on the other - simple for making a common ground. here's a picture of one of them.


second off, your switches. i think you mean SPTT (single pole, triple throw) and it sounds like you have a good concept for a slide switch at least. it might be easier to find a DPTT though. wire the battery in to the common wire on it, then wire each LED die to the individual poles. good plan indeed, but you'll need a main power switch to turn it all on and off unless you somehow come across a quad throw slide switch.

Cheers!
Az

[obiwanwasabi]

Thanks for replying!

I meant single pole single throw - just the basic push button latching switches sold at TCSS. So you push a button, circuit to one of the diodes closes, saber lights up. Push more buttons and the colour changes as the other diodes light up. Push a button again and that particular diode (die?) switches off (ie, no master switch - just a switch for each light on the LED). Am I on the right track for something that simple?

Here I was feeling reasonably pleased that I'd learned the difference between momentary / latching, and now I find out there's such a thing as a sliding DPTT!

[Azmaria Dei]

lol yeah! there are a LOT of different switches out there. yeah you could do it with 3 separate SPST latching switches too. if you go that route, i would go with the DX RGB since those mix to such a nice violet color without too much trouble. ^_^ and the round switches are a LOT easier to make holes for.

[pointoforigin]

I'm pretty sure that the particular black saber you describe is mass produced by a reputable saber smith company. I'm not sure of the pricing, and haven't searched for it and given a link out of respect for Tim. There is another large lightsaber forum that I'm sure you can find and get information on them from though. Youtube may yield some decent results also.

That said, if it's a custom creation that your boy really wants, it does look like you're on the right track. Mat Thorn did some excellent work in those threads, and explained a lot of things. I'm fairly certain that the LED used in that particular model saber mentioned before is the dealextreme RGB that Azmaria pointed out. It's cheap enough that you could get a couple, break one finding how it works, then make a good version.

[obiwanwasabi]

Thanks all. I came across the site we're not talking about early in my Googling and while they definitely have some sabers that look close, I couldn't see this particular one - the buttons were pretty distinctive. Good to know that the LEDs from the other site we're not talking about can do a reasonable job.

Re the wiring - have I got the basics OK? Positive from the battery to the switch the positive terminals on the LED; negative from the master negative on the LED back to the battery? I'm a bit fuzzy on the negative connections on the LED itself. Maybe if I have another look at some RGB led data sheets and see if they make sense this time.

I can see why this is such an addictive hobby. I suspect Luc's Hasbros will soon get to say hello to my favourite torture droid, DR3-M3L, so we can move the bits inside to something a little less mass market.

[Silver Serpent]

Yes, your wiring should work fine. The diagram you have in your first post will allow single colors, as well as simple color mixing (turn on red + blue = purplish).

Connecting all the negatives on the LED itself might be a bit tricky, but manageable with a little planning. I'm sure your son will love it when you get it finished.

Edit: Didn't notice Azmaria's recommendation for CREE LEDs. Having all the negatives on the same side would definitely simplify things.

[obiwanwasabi]

That's great news (and your sig seems especially apt at the moment). Just working out whether / how the TCSS blade holders will fit into our metric PVC - guess if it's tight I can always grind away a little PVC, and if it's loose I can add some filler. Off to the hardware store!

[diabetic8]

No one really replied if the three button guid was correct.