LED Strip - Swapping Wires

Thread Starter

THRobinson

Joined Jun 7, 2018
82
Looking to make an Xmas ornament that lights up but want one small section to light up a different colour.

Don't have a strip to play with so figured I'd ask first before buying it.

If I cut the end section off a USB powered LED strip, and ran wires to it, but instead of BRGB to BRGB, I were to swap the wires around so BRGB to BGBR for example, would it light up? So when the red is on the strip the small section will be green? And on cycle mode the small section will cycle put of colour-sync from the rest?

And, same sorta idea of crossing wires, I've seen LED bulbs with 4 leads, if I got a 5v one would it work off a strip?

Basically trying to 3D print one of those Deathstar tree toppers from Hallmark for someone. Figured I could make one for under $30, instead of buying one for $300.
 

jiggermole

Joined Jul 29, 2016
161
yeah but youd have to be real careful about the type you get. Most are power and data so swapping two wires would just make sure it stops working. I think the ones that are a full strip with the remote control are the best bet for ones that use red green blue ground, instead of D+, D-, +V, gnd. the ones that are definately data are the WS2812 ones.
I know its not specifically what you're looking for but this is one on amazon that if you zoom in real close you can see +, r, g, b, gnd on the led driver so this one would for sure do what you want.
 

BobTPH

Joined Jun 5, 2013
8,664
As stated in the last post, you need to get a strip that has R, G, B and either gnd, -, or +.

You can swap any of the R, G and B. The other one must remain the same.
 

Thread Starter

THRobinson

Joined Jun 7, 2018
82
At my PC now (not phone) so can make an image... sounds like what I was thinking is do-able.

Now, at the end, instead of cutting off the end of the strip and soldering on wires criss-crossed, would something like this SMD work? or an LED ring? Was looking around late last night but couldn't find 4-wire rings just 3-wire though.

Just looking at options. Need to order asap and not AliExpress or eBay because well, almost Dec already and niece just brought this up 2 days ago so, probably just grab a USB powered LED strip for behind the TV, sometimes Dollarama has them. Downside is that the cut lines are usually 3-4 leds apart and for the small part I just need 1 or 2. Ideally I find a strip like the image below that is USB powered and has a remote.

5v-RGB-30-60-LED-800x800.jpg
 

Ya’akov

Joined Jan 27, 2019
8,974
Just a heads up: I have a couple of RGB strips where the PCB is labeled like that but the LEDs are not GRB, they are RGB. It took a few minutes to figure out why my controller was acting so strangely.
 

Ya’akov

Joined Jan 27, 2019
8,974
Just looking at options. Need to order asap and not AliExpress or eBay because well, almost Dec already and niece just brought this up 2 days ago so, probably just grab a USB powered LED strip for behind the TV, sometimes Dollarama has them. Downside is that the cut lines are usually 3-4 leds apart and for the small part I just need 1 or 2. Ideally I find a strip like the image below that is USB powered and has a remote.
Look for 5V strips (USB or otherwise). The reason some have groups of 3 or more LEDs is the supply voltage. The LEDs are wired in a series to raise the voltage they can handle.
 

MisterBill2

Joined Jan 23, 2018
17,827
How about forgetting the LED strip and just getting actual LEDs that have wires to connect to? Just plain LEDs are available individually or in quantities up to about 100 in a bag. Much better looking that the LED tape, at least I think they are. And you are not paying for what you do not need.
 

Ya’akov

Joined Jan 27, 2019
8,974
How about forgetting the LED strip and just getting actual LEDs that have wires to connect to? Just plain LEDs are available individually or in quantities up to about 100 in a bag. Much better looking that the LED tape, at least I think they are. And you are not paying for what you do not need.
The difference in labor is enormous. The LED strips have a huge number of LEDs on them, as many as 300 chips in 5m, plus resistors. There are pre-wired daisy chains that are 5mm LEDs with wire between them but the amount of work to make either of these things from parts is... too much.
 

Thread Starter

THRobinson

Joined Jun 7, 2018
82
How about forgetting the LED strip and just getting actual LEDs that have wires to connect to? Just plain LEDs are available individually or in quantities up to about 100 in a bag. Much better looking that the LED tape, at least I think they are. And you are not paying for what you do not need.
Doing a Death Star tree topper (like this) so idea is print in 3 pieces, top, bottom and the middle ring/band. I'll put the strip on the band facing inwards so it'll be more an ambient glow vs bright spots, and it'll be inside a white 3D printed ball so, won't see the strip anyways. Plus, the strip is done, wired, has USB plug, remote etc.

The rear one has flashing lights, ambient glow, music and all sorts of sh*t... I'd be happy to have mine glow and if possible that death ray part glow as well a different colour from the rest. Figured print 1/2 a sphere, line with aluminum foil to block light getting in/out and it's in there that I want the small LED strip or better, a single bulb. But, I don't want to deal with anything more than solder, and if needed, adding a resistor... that's it. I'm not an electronics guy, I mostly just solder together guitar wiring. :D

So, unless I missed it, I don't think anyone's mentioned the single LED bulb or RING... would those work? Advice on how? I have seen some 4-lead bulbs, not sure if that'll work?
 

MisterBill2

Joined Jan 23, 2018
17,827
Looking at post #1, the TS is stating that they want to make AN ornament, which implies ONE assembled thing. Of course it may be that the goal is a garish object, but then it may be a delicately illuminated item done in good taste. So the need to use many LEDs is not so clear.
 

Thread Starter

THRobinson

Joined Jun 7, 2018
82
Looking at post #1, the TS is stating that they want to make AN ornament, which implies ONE assembled thing. Of course it may be that the goal is a garish object, but then it may be a delicately illuminated item done in good taste. So the need to use many LEDs is not so clear.
Last paragraph of OP says exactly what it is.. Hallmark Death Star... So it needs many lights, and it is indeed garish. :DI hate Star Wars, also hate Christmas... So I get 0 pleasure from this project, apart from making my niece happy because her (soon to be) in-laws are big Star Wars fans.

It was ok... But I don't get the continued hype for those movies. But also not a factor I guess when it comes to the electronics.

Initially I was going to use a full sized led rgb light bulb, but, need a socket and more heat and electricity etc... On top of a dry tree inside a 3d printed ball, made me nervous so thought led strip instead.

They will be hidden, so that garish aspect of the build is fine, but ya, it's still a death star on a tree.:confused:
 

Ya’akov

Joined Jan 27, 2019
8,974
Unfortuantely the cheap and… mirthless(?) constraint of the project, particularly the very low effort part, precludes a really good solution.

The rings you mention are, in my experience, always populated with individually addressable RGB(W) LEDs. These use data lines to control their own brightness levels for the three or four chips they contain. This requires a controller of some sort that can produce the data stream.

The best way to build what you want, ignoring the low-effort aspect for the moment, is to use an MCU-based (Microcontroller Unit) device such as an Arduino compatible development board. This is actually easy in the end but does require some up front investment in learning.

The truth is, you’ll probably finding knowing how to apply an Arduino compatible device fun and very useful well beyond this project, and it will make the behavior of the LEDs in this project infinitely adjustable doing whatever you might want. If also gives you the ability to add cool stuff—for example, and MP3 player module to add sound effects, and a proximity detector to make the thing interactive with people coming to look at it.

Of course it will take a few hours to learn enough to make the basic project but I suspect, in the end, not much longer than the struggle to cobble together parts not meant to do what you want in an arrangement that (mostly) does it.

If you are interested in taking the Arduino route, I guarantee you will get plenty of help from many members here, and I strongly suspect you will find your ability to use the Arduino development environment akin to a superpower that you can’t stop finding uses for.

Either way, good luck with a project you certainly seem to wish you weren’t doing!
 

ElectricSpidey

Joined Dec 2, 2017
2,756
I think this is a perfectly good solution, based on the description in the OP...no need for the rabbit hole.

1700149654947.png
You could also simply split the string and use a splitter at the controller and rearrange the connections there.
 

Ya’akov

Joined Jan 27, 2019
8,974
I think this is a perfectly good solution, based on the description in the OP...no need for the rabbit hole.
And, for my part I think the TS would get more benefit from stretching a bit and acquiring a tool that will do a lot more than just this project. It is a perfect fit to go with his 3D printing capability, and misleading in its apparent difficulty.

I do believe that it will take a similar time to do this kludgy way to doing it with a MCU and will not be nearly as good nor as close to what is wanted. And, when it is done the time will not have been an investment in anything, just an expenditure.

On the other hand, as always, I consider it a choice for the person who is doing the thing to make. My goal is to be as sure as I can that what my experience tells me is a superior solution is an option to be considered.
 

Thread Starter

THRobinson

Joined Jun 7, 2018
82
I have a small Arduino learning kit. Bought for my nephew, he hated it so felt bad and bought it back from him. :D

That said, I'm in college full time for accounting, at age 48, so that Arduino has sat gathering dust. Wanted to make a simple CNC guitar pickup winder with it, but the feedback I got for it was all over the place, flip flopped back and forth and even got a bit heated, so never bothered, just went basic old school hand winding.

That said, Arduino looks fun... But no time, too pricey and heavy for a tree topper, and not sure about the small ones but stuff like Raspberry Pi is horribly priced right now.
 

Ya’akov

Joined Jan 27, 2019
8,974
I have a small Arduino learning kit. Bought for my nephew, he hated it so felt bad and bought it back from him. :D

That said, I'm in college full time for accounting, at age 48, so that Arduino has sat gathering dust. Wanted to make a simple CNC guitar pickup winder with it, but the feedback I got for it was all over the place, flip flopped back and forth and even got a bit heated, so never bothered, just went basic old school hand winding.

That said, Arduino looks fun... But no time, too pricey and heavy for a tree topper, and not sure about the small ones but stuff like Raspberry Pi is horribly priced right now.
You could do what you want with an 8-pin integrated circuit (ATTiny85) for a couple of dollars, a cheap programmer (~$5-$10), the LEDs, one tiny capacitor, and a partial handful of resistors. The entire thing could be put on a protoboard about the size of a large postage stamp.

Or, you could use a cheap development board for about five bucks, and it would be marginally easier and maybe 50% bigger.

But, if you are not enthusiastic about going that route, it’s probably not the right path for you. I hope the alternative goes smoothly and quickly!
 

Thread Starter

THRobinson

Joined Jun 7, 2018
82
You could do what you want with an 8-pin integrated circuit (ATTiny85) for a couple of dollars, a cheap programmer (~$5-$10), the LEDs, one tiny capacitor, and a partial handful of resistors. The entire thing could be put on a protoboard about the size of a large postage stamp.

Or, you could use a cheap development board for about five bucks, and it would be marginally easier and maybe 50% bigger.

But, if you are not enthusiastic about going that route, it’s probably not the right path for you. I hope the alternative goes smoothly and quickly!
Ya, needs done in under 2 weeks, and on the cheap because a tree topper that's only used a few weeks a year, so, $2-5 LED strip and a USB extension cable is fine for this project.

Still would like a CNC operated pickup winder though, but, school comes first for now. New hobbies later. :D
 

Ya’akov

Joined Jan 27, 2019
8,974
Come back when you have questions. I am sure you will have a lot of fun (and some frustration, though not enough to cancel the fun).
 

Thread Starter

THRobinson

Joined Jun 7, 2018
82
Finished today... Took 5 days to print, after a few days of fighting with the file. Originally it was a solid one-piece print, which I made hollow and added a snap fit ring inside that worked better than expected.

Dollarama had a strip of LEDs with remote and sound sensor, $4 I think it was. Printed a small cone to go behind the death laser part of the Death Star and mounted 2 leds from the strip inside and swapped the wiring around.

Works great, plenty lit up. Made a small video testing the multiple light modes. Will shrink and attach... Just tried now and too big.

Just need a long male-female USB extension cable and an old USB phone charger.
 
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