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3W RGB versus Pixie
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3W RGB versus Pixie

by zara2355 on Sun Sep 08, 2019 4:59 pm

Hello all,

I am creating a project and was hoping for some product advice...

For the project, i am using Processing to grab 3 pieces of weather data (temperature, humidity, and wind speed), from a total of 8 cities and then send those numbers to an Arduino. The Arduino will use the three numbers from Processing as RGB values to change the color of 8 LEDs (one LED per city). These LEDs will then be connected to side glow fiber optics.

Apparently, Im going to need something strong. (Stronger than a regular LED, or even an Ultra brite)

What i've come down to are either the 3W Common Anode RGB LED (prod # 2530), or the Pixie (prod # 2741).

Obviously, there are pros and cons to each, and to be honest, Im not entirely sure how to deal with the power supplies. (Im assuming 1A per light?)

Ive tried looking through the tutorials on how to properly (and SAFELY) wire either light, especially multiple lights. (i.e. i've read using drivers for the RGBs??) is there a tutorial/forum post somewhere that shows this that i missed? Additionally, since i need 8 lights, would the 3W RGBs run out of pins?

Any advice/help is greatly appreciated! Thanks in advance

zara2355
 
Posts: 104
Joined: Tue Jun 18, 2013 6:43 pm

Re: 3W RGB versus Pixie

by mikeysklar on Sun Sep 08, 2019 6:26 pm

Hi zara2355,

I would use the Pixie LEDs as they are chainable leaving you plenty of pins for other applications.

The Guide "Pixie - the 3W Chainable LED Pixel" provides an excellent walk through using an Arduino or Feather M0 with CircuitPython.

https://learn.adafruit.com/pixie-3-watt ... s/overview

Checkout the wiring diagram for the feather M0 which will be the same concept TX and GND for an Arduino application.

https://cdn-learn.adafruit.com/assets/a ... 1531863688

mikeysklar
 
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Re: 3W RGB versus Pixie

by zara2355 on Sun Sep 08, 2019 8:03 pm

Thanks for the reply, I was leaning towards Pixies already.

So, i guess the question i have left would be, what sort of power supply would be appropriate? Would i choose something like 5V/10A? (a little extra current draw to be safe)? WOuld i need any other components to ensure success in terms of power with the Pixies and the Uno?

zara2355
 
Posts: 104
Joined: Tue Jun 18, 2013 6:43 pm

Re: 3W RGB versus Pixie

by mikeysklar on Sun Sep 08, 2019 9:40 pm

I'd pick these up. The Female DC Power adapter will make for a solid connection to the circuit.

5V @ 10A for the power supply
https://www.adafruit.com/product/658

Female DC Power adapter - 2.1mm jack to screw terminal block
https://www.adafruit.com/product/368

mikeysklar
 
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Re: 3W RGB versus Pixie

by XRAD on Mon Sep 09, 2019 11:33 am

Definitely read the pixie guide. They require a 'pixie' library. They will time out if too hot or if not receiving code updates, but these things are easy to avoid. Pixies are a great choice and plenty bright for fiber.

XRAD
 
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Re: 3W RGB versus Pixie

by zara2355 on Mon Sep 09, 2019 7:58 pm

Thanks a million XRAD and mikeysklar, really appreciate it.

Ok, one more question, if thats ok....

Are there any good tutorials about adding heat sinks to the Pixies? I've read in the forums about "potting", but i dont know what that is, aside from that it seems to be some sort of epoxy. I would rather not use chemicals....if possible, an aluminium sink .

Again, thanks a million

zara2355
 
Posts: 104
Joined: Tue Jun 18, 2013 6:43 pm

Re: 3W RGB versus Pixie

by mikeysklar on Tue Sep 10, 2019 3:44 pm

Any sort of finned aluminum will make a decent heat sink. Probably best not to drive these at full brightness to stay in a safe zone. Adafruit sells a 10 pack of aluminum SMT heat sink that could help:

https://www.adafruit.com/product/1515

If they will all be side by side you could use a long rail of finned aluminum stock.

https://www.ebay.com/itm/High-Power-LED ... 2071244358

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Please be positive and constructive with your questions and comments.