Author Topic: Individually addressable RGB LED comparison?  (Read 126372 times)

DavidWow

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Re: Individually addressable RGB LED comparison?
« Reply #30 on: October 01, 2013, 01:10:50 pm »
thanks so much guys!
Seemingly encouraging responses.
So far none of you have just flat out said, 'No, it wont work',
so I feel assured!
I will definitely begin testing now.

carl125

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Re: Individually addressable RGB LED comparison?
« Reply #31 on: November 18, 2013, 08:49:29 pm »
The WS2811 light strips I currently have are ws2811 strip which are 60 LEDs/m on white flexible circuit and IP67 waterproof silicone sleeve.

I see that they now have a new product with 144 LEDs/m ws2812, really want to take a try.

MOD EDIT: Links removed, this message is probably spam - but the 144 LED/m strips do look cool
« Last Edit: November 18, 2013, 09:31:32 pm by digistump »

DeuxVis

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Re: Individually addressable RGB LED comparison?
« Reply #32 on: December 20, 2013, 04:26:23 am »
Dougal, do you have any figures on the number of failed WS2812 you found in your Ebay delivery ?

Yesterday night I finally took some time to solder 4 of mines "deadbug mode" on 2.54mm headers to plug them in a breadboard for testing, and only 2 of them are working.

It might be bad luck or bad soldering / overheating, just curious what you experienced on your side.


EdIt : oh by the way don't know if this was mentioned before, the Adafruit Neopixel library seems to be working out of the box on a digispark to talk to those leds.
« Last Edit: December 20, 2013, 04:49:38 am by DeuxVis »

dougal

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Re: Individually addressable RGB LED comparison?
« Reply #33 on: December 20, 2013, 06:08:08 am »
I haven't had a chance to try doing anything with my batch of raw WS2812 modules. For one thing, the only soldering method I have is my Weller iron, and I don't have a tip fine enough to work on small connections like that. I had ordered a new tip for working on small parts, but it turned out to be the wrong size for my iron.  :-\

I really need to look into stuff like solder paste, heat guns, and reflow ovens one of these days. But I don't see that happening anytime soon, unfortunately.

But yes, there have been several threads here where we've talked about the Adafruit NeoPixel products and libraries. For a while, I was plugging my Digispark into my car's USB power port and dangling a NeoPixel ring from my rearview mirror while I drove. I'm thinking I need to route one to the front of my car as a "Rudolph nose" for Christmas.  ;D

digistump

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Re: Individually addressable RGB LED comparison?
« Reply #34 on: December 20, 2013, 08:35:03 pm »
Out of about 80 ws2812bs I had 4 bad ones (one color didn't work) after replacing those I had more - I finally concluded that if you get them too hot the green LED goes out first, then blue, then red. Reflowing them instead of iron worked better with none dead. These were straight off the reel that I bought to sell on digistump.com.... so yeah I should probably add them to the products instead of just playing with them

Bluebie

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Re: Individually addressable RGB LED comparison?
« Reply #35 on: December 27, 2013, 02:22:42 pm »
This aligns really well with my experience with 5050 leds - you need to be quite quick when soldering them, or get an aligator clip and clip it on to the contact to try and suck some of the heat away. So make sure your soldering iron is at the right temperature and everything is working quickly before soldering those things. Also keep in mind that with ws2812 strips, the strip itself is full of copper which acts as a little heatsink for the lights. It maybe a good idea to try and design v+ and gnd traces on PCBs to work as a little heatsink if you can :)

defragster

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Re: Individually addressable RGB LED comparison?
« Reply #36 on: December 27, 2013, 09:20:18 pm »
Just yesterday I pulled this detail that might prevent the production of many future photons:

     Sparkfun Green SMD . . .   Be quick–five seconds at 260°C can cook them.

260° Celsius = 500° Fahrenheit [ conversion for those of U.S. not wanting to rush the adoption of the Metric System ]

* In 1866, Congress authorized the use of the metric system in this country and supplied each state with a set of standard metric weights and measures. In 1875, the United States solidified its commitment to the development of the internationally recognized metric system by becoming one of the original seventeen signatory nations to the Treaty of the Meter.
http://www.nist.gov/pml/wmd/metric/upload/1136a.pdf

DeuxVis

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Re: Individually addressable RGB LED comparison?
« Reply #37 on: January 07, 2014, 02:52:13 am »
Yup that was probably my noob soldering mistake, I was using full power on my iron (450°C).

I did solder a few more since then, using less temperature (300 to 350 °C) and watching the heating timing. None failed yet.

Neon22

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Re: Individually addressable RGB LED comparison?
« Reply #38 on: February 10, 2014, 04:13:33 am »
See new way to drive these using SPI interface and a couple of transistors:
- http://rgb-123.com/ws2812b-vs-ws2811/

DeuxVis

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Re: Individually addressable RGB LED comparison?
« Reply #39 on: February 11, 2014, 07:04:34 am »
See new way to drive these using SPI interface and a couple of transistors:
- http://rgb-123.com/ws2812b-vs-ws2811/

Maybe I'm getting blind but I can't see anything about SPI on the page you linked ?!?

dougal

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Re: Individually addressable RGB LED comparison?
« Reply #40 on: February 12, 2014, 11:21:02 am »
I'm guessing that Neon22 accidentally pasted the wrong link, and meant to post this one, recently featured on Hackaday:

http://wiki.artifactory.org.au/doku.php?id=projects:ws2811clockshaper

DeuxVis

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Re: Individually addressable RGB LED comparison?
« Reply #41 on: February 21, 2014, 05:06:35 am »
Thanks Dougal, interesting reading.


I took some pictures of my attempts to use those WS2812 on a breadboard for prototyping, thought I would share.


The first try was to solder them on angled headers, after bending the header's outer pins toward the middle one so they're somewhat aligned with the led pads.
This is when I burned some leds, I was using too much temperature and stayed too long on each pin because of the bad alignment with the header and they large thermal dissipation.
If I was again to try something similar i would probably use some thin wire instead of the headers.


After that I made some simple PCBs by toner transfer and chemical etching. That's already really easier to solder, but using flux is needed (mostly because of the poor quality of my PCBs).


Then I did a new PCB design adding the passive components needed to spare space on the breadboard.
That was the first time I designed a PCB for "industrial" making, I ordered those - the green ones - from seeed studio.
I realised a little too late that I put the pads on one side and the traces on the other side, with nothing linking them  :-\
To learn my lesson I used them anyway, recreating the connection with wire and components legs remnants.
Man this solder mask thing makes it so easy to solder the surface mount components ! No flux needed here.
I think this is actually faster to solder than a through hole version would be - not counting the wiring step that you shouldn't need to take if you double-checked your design in  gerber viewer before ordering...


Then I made a "final" version and ordered it from the fritzing fab service. It arrived two times faster than from seeed studio but cost me five times the price.
Now I can play with them on a breadboard :)

gogol

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Re: Individually addressable RGB LED comparison?
« Reply #42 on: February 21, 2014, 08:06:37 am »
Question: Why you have choosen the older six-pin version WS2812 and not the four-pin WS2812B, when you spent so much effort in PCBs?

dougal

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Re: Individually addressable RGB LED comparison?
« Reply #43 on: February 21, 2014, 12:40:35 pm »
I'd probably do the same thing. Why? Because I already have the 6-pin variety on hand, because I bought a lot of 100 of them a while back. :)

gogol

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Re: Individually addressable RGB LED comparison?
« Reply #44 on: February 23, 2014, 11:58:35 pm »
ok, that is one reason I have not thought upon.   I thought, that I have missed some other technical detail, making the 6-pins more valuable. ;-)