The 1200 sequenced LED party pants: A step by step

[junglesmacks]

WOW.

All I can say is wow. The experiences I had with the suit this year were awe inspiring to say the least. People literally were riding bikes across playa to see what it was they were seeing in the distance. The flood of people coming up to me that were just speechless with a simple smile and high five was just.. wow. Floods of people. Non stop "Thank YOU for that!!". Just.. no other words but awe inspiring. My favorite overall would have to be walking mid playa when a girl comes up to me on a bike.. says.. "WAIT!". Stops her bike and gets off.. checks me out.. takes a few steps back.. and says to me with her hands up in the air.. "Dude.. you WIN. You win. Best.. ever. Rock on.." ..and rides off.


Did any of you out there see me? Get any pictures? Please.. let me know. I'm dying to see one.

As far as the design goes, the major and only weak point was using fabric as a base to mount the LEDs. The flexing and partying would snap the fragile summed ground and positive chains and require a couple hours worth of work the next morning soldering by generator while "hungover". Not fun. They really need either a rigid backing, or possibly if you were to take stranded copper wire and solder a line of that as a basis for all of the chains. Personally, I'm looking right now at getting custom PCBs produced so that I can have a perfect backing to solder everything to, then mount those via epoxied snaps to the clothing. Since I'm having custom boards made up, why not get a bunch made.. and.. hmm... start a little business making suits for others..


It's happening.

[trilobyte]

I wish I'd gotten to see them in action, the project is smothered in awesome.

What about using some kind of thicker rubber or plastic base for the PCB's? That way there's some give, but not so much that it's going to screw up your connections with normal wear. Another option is to look into conductive threads - not sure if it would work for the kind of current you're using, but my girlfriend used it to sew some LED's (not any kind of significant quantity, and just a simple self-contained pulse glow), and I think it worked pretty well.

[junglesmacks]

Totally. My tentative plan is to get the PCBs made/make them myself, and have a mounting hole on each corner for a spacer with a screw. Have identical sized plexiglass panels made out of say.. 1/4" or 1/8" plexiglass.. and mount the board to that. Then, epoxy snaps on all 4 corners of the underside of the plexiglass with matching snaps on the pants/shirt. This should allow the whole assembly to be decently lightweight, while allowing me to simply unsnap the boards for transport or.. my favorite.. changing color combos Imagine one night being red/yellow. another night pink/green.. or building custom panels that are a combo of colors.. or.. whatever you want! The possibilities are infinite.

To that end, if anyone out there has any contacts in the custom PCB industry, please pass them along. I've been pricing them out and they are not cheap. Right now I'm looking at about $1.51/board for a 3"x3" and buying 250 at a time.

I wish I'd gotten to see them in action, the project is smothered in awesome.

What about using some kind of thicker rubber or plastic base for the PCB's? That way there's some give, but not so much that it's going to screw up your connections with normal wear. Another option is to look into conductive threads - not sure if it would work for the kind of current you're using, but my girlfriend used it to sew some LED's (not any kind of significant quantity, and just a simple self-contained pulse glow), and I think it worked pretty well.

[BBadger]

How about using Wire Wrap? Far more mechanically sound than soldering, and a lot cheaper than PCBs (though not necessarily cheap).

[junglesmacks]

Let me know if you find them much cheaper than $0.15 each for 4-pin common anode/cathode LEDs. I'd like to buy large quantities for a good price too.

This guy was who I purchased all of my LEDs from: http://www.ebay.com/itm/1000-pcs-5mm-4- ... 2c5e983b82



EDIT: Oh *snap* on the shipping charges!

[Key Man]

Very impressive and nice work! You've got me thinking about doing something similar (albeit on a smaller scale) next year.

Just a couple of quick thoughts. The resistors are wasting a bit of power. Not sure what your running voltage is, but couldn't you wire it with LED's only, in series strings with the LED voltage drops equaling the source voltage? Might be simpler that way, too.

Also, you might consider litz (fine fabric woven) wire for the interconnects. It will bend and flex over and over without breaking. It's a pain to solder (some kind of mini crimps might be easier and faster) but it would reduce your breakage issues and might make the costume more comfortable.

But these are just ideas from afar, you know your project much better than I do. Congrats on conceiving and bringing it to life! Very nice, and wish I'd seen you on the playa.

[junglesmacks]

Very impressive and nice work! You've got me thinking about doing something similar (albeit on a smaller scale) next year.

Thanks so much for the kind words! My feedback is that every single last little bit of blood sweat and tears you pour into your lighting project will be worth it once you get to the playa. Go big.. VERY Big. Take what you are dreaming now, and multiply it by 5 or 10 times. Do it! You have the time! The gratitude and amazement by fellow atendees will blow you away. I'm more than happy to help with any and all things LED/electronics that I can as are others on this board. Let's do it!

Just a couple of quick thoughts. The resistors are wasting a bit of power. Not sure what your running voltage is, but couldn't you wire it with LED's only, in series strings with the LED voltage drops equaling the source voltage? Might be simpler that way, too.

While the resistors are indeed wasting a little power, it's nominal and needed to keep from burning out the LEDs. Look at the beginning of my post where I explained the battery pack and subsequent source volatage that I'm using. Typically, you will find battery packs in the 3v or 6v or 9v range as this would be either 2 or 4 AA or a single 9v battery (1 AA battery = 1.5v). So my choices were pretty much limited to a source voltage of either 3v, 6v, 9v, 12v, 18v. Being as that I was going to do 5 x 15 rows of LEDs, for the ease of soldering the chains together I would do one resistor per chain of 5. Since green or blue LEDs need 3.2v per LED, this would mean that I needed 16v per chain to run them. So, 18v was the best option. Since I knew my source voltage and the forward voltage per LED, I could plug those into the wizard via the link that I posted to find the proper resistor value. Very easy. Keep in mind that while resistors do dissapate ("use") energy, they mainly just slow the flow. Kind of a technical discussion. Check out this link for a quick synapsis: http://www.candlepowerforums.com/vb/sho ... uot-energy

Now.. I'll tell you this much. I ran them at 15mA forward current initially with the 150 ohm resistor per string, and oh my god they were BLINDING when all put together. For individual LEDs on the playa, sure go with 15mA. But if you are making huge groups of them together you will be downright obnoxious if you don't town them down. I actually made little inline plug-ins using 300ohm / 1/2 watt resistors per channel to tone the whole thing down. So essentially, I actually was running a 450 ohm resistor per channel instead of a 150 ohm.. and I was so bright that people from over a mile away were seeking me out on bikes thinking that I was an art installation! This means that I was really only running those LEDs at around 5mA per LED!! Also.. I never changed batteries even ONCE.. and still have plenty of juice in them leftover after the burn.. and they are still so bright that I need the resistor packs. Seriously. Next time, I'm using a pair of 9v snap type batteries to save weight. I really didn't need to cart around 12 AAs with me all night.

Also, you might consider litz (fine fabric woven) wire for the interconnects. It will bend and flex over and over without breaking. It's a pain to solder (some kind of mini crimps might be easier and faster) but it would reduce your breakage issues and might make the costume more comfortable.

The weak point on this wasn't the LEDs twisted together, it was the summation of all the ground and positive wiring along the edges. In hindsight, I should have used say simple solid core 22AWG hookup wire just spiraled around it and soldered to it as a base. This is what would crack and break each night from flexing and bumping into stuff while partying. The twists on the LEDs held up fine.. it was just those long chains of ground with the pins bent over and soldered together. In TRUE hind sight, the base of becoming a weak point was using fabric squares with no rigidity to them as the basis for a panel of so many LEDs. You need something rigid, as not only do they flex but the LEDs bend over and you are always straightening them and stressing over it. Ideally, you need to solder them to a PCB. That is exactly what I am doing for next year. I'm talking now to PCB manufacturers and having custom PCBs made up that I can solder all of the LEDs and resistors to it. You could also just get basic breadboard/greenboard and solder jumpers and traces yourself.

But these are just ideas from afar, you know your project much better than I do. Congrats on conceiving and bringing it to life! Very nice, and wish I'd seen you on the playa.

Again.. you and everyone and the entire playa is so very welcome and I'm honored to have brought the gift of lighting to the playa. I'm pleading with the whole community on this one..

PLEASE BRING MORE LED LIGHT ART TO THE PLAYA!!

We need more! More!! LEDs along with fire and neon are truly what bring our night cityscape to life. EL wire is worthless and so expensive. You can't see the stuff farther than about 30 ft, and chemical glow products are HORRIBLE and make me want to gag. You can't see them and they are nothing but pure global MOOP. LEDs are cheap as anything.. easy to work with.. and you can make such incredible designs with them so well. Poke some through your backpack, jacket, skirt, hat.. whatever.. wire them.. attach a simple battery.. and voila! Instant, custom night art that you can see for miles. So awesome.

If you don't feel like dealing with resistors, you can even buy strings of lights or individual lights with resistors pre heat shrunk on already such as this: http://www.ebay.com/itm/B-50X-5mm-pre-w ... 5d3052fab3

All you would need is just a battery pack that matches.. you could even run these off a simple 9v snap battery. Get the harness from like here: http://www.allelectronics.com/make-a-st ... ers/1.html

It's soooooo simple.. it really is!

HOW CAN I HELP YOU DO THIS?

[percussivepaul]

Hey junglesmacks. I'm planning an LED project and interested in battery life and heat.

I'll have about 100 RGB LEDs sequenced by a microcontroller. I will want this thing to be running all night, or most of the night, and it is small and portable so I want light batteries. You said you were running this thing off of 12 AA's for the whole week? Did you ever measure the current draw from the whole suit? It's not adding up in my head; with 1000 LEDs at 5mA each as you say, I don't see how you could get more than a few hours of juice.

Also heat. The 100 LEDs and microcontroller will be in a pretty small enclosed space and I'm a little concerned the microcontroller might overheat, either because of the computational load, or the extra heat from the LEDs. Do these things get warm at all in high densities?

[trilobyte]

Hey now, let's not go knocking on EL-wire. It may not suit your project's purposes but it's hardly worthless. Depending on the thickness and type of wire used, it can easily be seen from further away, and besides... sometimes you may not want to shine a light that can be seen from across the playa.

[junglesmacks]

Hey junglesmacks. I'm planning an LED project and interested in battery life and heat.

NICE! Do it do it do it DO IT!

I'll have about 100 RGB LEDs sequenced by a microcontroller. I will want this thing to be running all night, or most of the night, and it is small and portable so I want light batteries. You said you were running this thing off of 12 AA's for the whole week? Did you ever measure the current draw from the whole suit? It's not adding up in my head; with 1000 LEDs at 5mA each as you say, I don't see how you could get more than a few hours of juice.

With 100 LEDs, you could seriously run them off of watch batteries and be fine.. or a simple 3v 2 - AA battery pack. It's amazing how much battery power LEDs do NOT use. You can get a figure on total current draw from the LED wizard here: http://led.linear1.org/led.wiz. Put in your specs, and it will give you a total draw by mA for the total array. You can do rough calculations by mAH ratings of the batteries you are using. In reality, it will be more because as the power goes down, it just gets a little dimmer.. not totally shut off.

Remember too that even though I had 1440 LEDs that I was powering, I had 8 channels sequenced for a total of 180 LEDs per channel.. so at any given time, only 180 LEDs were being powered at once. Well.. kind of. The sequencing pattern that I used had a slow fade out for the 3 channels behind the sequence as to give it a more "paintbrush" effect rather than just on or off. Meaning.. the lead channel in the sequence fired at 100%, the channel behind at 50%, and the one behind that at 25%. This gave it more of a moving, sweeping effect rather than just on or off blockiness. Explanation here: http://picprojects.org/projects/480/480 ... eqflow.jpg

So yeah.. I had way overkill in the battery department. I should have used 2 x 9v snap type batteries which is what I'll use next year..

Also heat. The 100 LEDs and microcontroller will be in a pretty small enclosed space and I'm a little concerned the microcontroller might overheat, either because of the computational load, or the extra heat from the LEDs. Do these things get warm at all in high densities?

You will have absolutely guaranteed zero problems with heat. Promise. Don't even figure it into the equation. If you were running 4000 LEDs at max load all the time, then maybe.. but 100 LEDs even at 100% duty cycle at 20mA isn't enough to make a fart in the wind. You'll be fine. Enclose that sucker up in a fanny bag or otherwise.


Good luck and let me know if you need any help! GO BIG!!