Author Topic: Individually addressable RGB LED comparison?  (Read 126369 times)

digistump

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Re: Individually addressable RGB LED comparison?
« Reply #15 on: September 04, 2013, 09:55:08 pm »
We'll be making some shields for them as well - which will also serve as mini breakout boards with the cap on them - possibly I'll add sewing holes as well.

dougal

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Re: Individually addressable RGB LED comparison?
« Reply #16 on: September 05, 2013, 05:55:10 am »
When I saw you mention before that you'd be selling the modules, my first thought was that I should make a tiny LED matrix shield (maybe 3x3 or 4x4). :)


I've never actually designed/created a circuit board before, but this seems like it would be a simple enough thing that I could cut my teeth on. You know, in my Copious Free Time;)

dougal

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Re: Individually addressable RGB LED comparison?
« Reply #17 on: September 05, 2013, 10:48:12 am »
Digispark + BoostMiniUSB + NeoPixel Ring = Fun!



Bluebie

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Re: Individually addressable RGB LED comparison?
« Reply #18 on: September 05, 2013, 05:09:27 pm »
For the future if you need to boost voltages up a bit to control something like that, hobbyking sells devices which can boost voltages, I think specced at minimum 2.8 or so but I bet it'd go lower than that, up to 5v. They cost like $2 each and are already assembled.

defragster

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Re: Individually addressable RGB LED comparison?
« Reply #19 on: September 05, 2013, 10:41:56 pm »
Nice tip - I find this 'TURNIGY Voltage Booster for Servo' for $3.37: http://www.hobbyking.com/hobbyking/store/__37813__TURNIGY_Voltage_Booster_for_Servo_Rx_1S_to_5v_1A_USA_Warehouse_.html
Operating Voltage : 3.2V - 4.2V
Operating Current : 1A
Max operating Current : 1.5A

defragster

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Re: Individually addressable RGB LED comparison?
« Reply #20 on: September 05, 2013, 10:55:06 pm »
Just saw this: http://www.pololu.com/catalog/product/2564
Pololu 5V Step-Up Voltage Regulator U1V10F5 $4.49
This tiny (0.35″×0.45″) U1V10F5 switching step-up (or boost) voltage regulator efficiently generates 5 V from input voltages as low as 0.5 V.  Unlike most boost regulators, the U1V10F5 automatically switches to a linear down-regulation mode when the input voltage exceeds the output.  The pins have a 0.1″ spacing, making this board compatible with standard solderless breadboards and perfboards.
Pololu step-up voltage regulator U1V10F3/U1V10F5 in a breadboard.
Also 3.3v and over 5v versions

defragster

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Re: Individually addressable RGB LED comparison?
« Reply #21 on: September 05, 2013, 11:05:38 pm »
http://www.pololu.com/catalog/product/2115 $3.95  and compact (0.32″×0.515″), input voltage as low as 2.5 V

Bluebie

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Re: Individually addressable RGB LED comparison?
« Reply #22 on: September 06, 2013, 01:32:51 am »
Great catch! Thanks for that @defragster!

defragster

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Re: Individually addressable RGB LED comparison?
« Reply #23 on: September 06, 2013, 02:02:02 am »
@Bluebie -  :)     Anxious to see Pro&Con review if there is anything better, it seems these are small and appropriate. 
I'm wondering if there is a way to stop the draw to save a battery if you miss a change.

dougal

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Re: Individually addressable RGB LED comparison?
« Reply #24 on: September 06, 2013, 05:44:57 am »
I was a Kickstarter backer for the BoostMini project, and I just received my boards a few days ago. So that's what I have on-hand. Yes, there are cheaper options, but that wasn't the point. ;D


Relaxen und watschen austounden das blinkenlights!


defragster

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Re: Individually addressable RGB LED comparison?
« Reply #25 on: September 06, 2013, 10:28:41 am »
Interesting find @Dougal - having something to use that works is the first goal.
http://www.kickstarter.com/projects/1257390142/boostmini-power-supply-and-voltage-converter

This was in the first 'unfunded' KStart

DavidWow

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Re: Individually addressable RGB LED comparison?
« Reply #26 on: September 30, 2013, 10:59:18 am »
Hey guys,

I have a couple projects that require chainable LEDs, but fairly spaced out (for one, I need possibly 10ft between them).  I was wondering if you knew the maximum distance the WS2811/WS2812s can be spaced from eachother, and from a microcontroller?

and/or if you can help me understand what would make a an LED circuit and its data transmission more or less reliable as far as distances are concerned?
Like, might the WS2801 somehow be more reliable because of the clock pin? 
Or do I need to go a whole different route for longer distances, like an SPI protocol, or some multiplexor??

thanx!

 

digistump

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Re: Individually addressable RGB LED comparison?
« Reply #27 on: September 30, 2013, 06:37:22 pm »
@DavidWow


First I'd say give it a try - you can these super cheap and thats always the best way to know for sure (since there isn't an official limit that I can tell)


I regularly run them 1 ft apart - but I've never tried 10 ft. I'd imagine they'll perform at least as well as SPI (SPI is often a much higher clock) and any buffer that can hit 800hz(I think?) (which should be easy) should be able to repeat the signal if needed.

dougal

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Re: Individually addressable RGB LED comparison?
« Reply #28 on: October 01, 2013, 06:54:07 am »
800kHz for WS2812. I've seen references that say they might work with the 400kHz timing, but haven't tried it myself. Strips that use WS2811 controllers separate from the LEDs work at 400kHz. And of course, the WS2801s are SPI and you control the timing via clock signal.


And yeah, I think that if the signal degrades too much for that distance, a buffer could do the trick. It shouldn't be hard to find one to handle the speed, but you'll want to make sure it can also handle the current requirements. From what I understand, the WS2811/2812 modules themselves act as buffers, and re-condition the data signal on output (if I'm wrong, somebody correct me). So as long as the signal coming in is good enough, stretching things out shouldn't pose too many problems.

Bluebie

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Re: Individually addressable RGB LED comparison?
« Reply #29 on: October 01, 2013, 06:57:36 am »
The datasheets for ws2812 and ws2812b LED modules (the type with integrated chip, in a four or six pin LED) specifies they are good for at least 5 meters (16 feet) between each light. Each LED cleans up the timing of the signal, so you can chain as many as you want like that. Do be aware of interference though. You might benefit from using twisted pair wires, like those found in telephone cable or ethernet. Twisted pair wires will help reduce the impact of any magnetic interference on the data by balancing it equally across ground and data lines. You also might benefit from adding a resistor in between each LED along only the data lines, to help soak up any reflections in the wires which might become more of an issue at those longer distances.