Just noticed these on eBay...

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(JP Roy) #1

Just noticed these on eBay…

http://www.ebay.com/itm/10-1000Pcs-APA102-5050-RGB-Prewired-10MM-3MM-Ragid-Board-LED-Pixel-LED-Chip-5V-/381276846464?pt=LH_DefaultDomain_0&var=&hash=item58c5def980

Many here mentioned that APA102 were only available in strip form and they were hoping to get them in different packaging.
http://www.ebay.com/itm/10-1000Pcs-APA102-5050-RGB-Prewired-10MM-3MM-Ragid-Board-LED-Pixel-LED-Chip-5V-/381276846464?pt=LH_DefaultDomain_0&var&hash=item58c5def980

(Marc Miller) #2

Nice find, thanks for sharing.

(JP Roy) #3

I have used the same package with WS2812b before, just look at my homemade matrix used for my recently posted fireworks display.

I find them more versatile than strips as they easily allow irregular spacing between the pixels.

I find them a bit expensive in that package for now but I guess they will come down in price eventually.

(Marc Miller) #4

JP, you built your matrix starting with that sort of package? That’s a lot of soldering to use those instead of using strips. Nicely done.

I’d be interested to see APA102’s in a “Christmas lights” sort of string.

(JP Roy) #5

Yes, that was indeed a lot of soldering !

To be honest, I had other ideas than a rectangular matrix when I initially ordered these WS2812b miniboards but that’s where they ended up for now !

(JP Roy) #6

@marmil For the Xmas light idea, I would be a bit worried with driving them high-speed devices with some lengths of wiring between them… Crosstalk, noise pickup and all !!!

(Roger Kolasinski) #7

True, I’ve purchased them several times, but the only way to get a deal is to buy them on auction – but don’t drive the price up bidding for no reason. I got my first 50 for $8.00.

(Mat Helm) #8

Consider an actually “Prewired” board… 16 x 16 (256) $62.99 usd w/free shipping
http://www.aliexpress.com/item/Free-Shipping-16-16-256-Pixels-WS2812B-Addressable-Ragid-LED-Screen-Board-Pixel-LED-Panel-Light/32271019696.html

(Mike Thornbury) #9

I just buy the SMD chip. They are about 15-20c each.

(JP Roy) #10

Ok if you can wave solder them but a real pain if all you got is a simple soldering iron !

(Mike Thornbury) #11

What’s wave soldering?

I just use solder paste and a $60 solder/hot air reflow gun.

Or put it in the oven when the wife’s out…

(JP Roy) #12

Hi @Mike_Thornbury ,

Sorry I did not use the correct terminology here… I did mean to say reflow soldering!

Wave soldering is a totally different methodology not applicable to smt.

It is a commercial PCB soldering process for older style through-hole components where boards on a conveyor belt passed just on top of a ‘wave’ of molten solder.

I am curious, do you have any pics or videos of your assembled APA102’s ?

(Mike Thornbury) #13

Nope, but I’ve just developed a new board which should arrive here in the jungle in about a month -it has APA102s. I can take some pics of that.

Home reflow is easy and cheap. Some of the better toaster ovens have a reflow setting (black and decker in NA, I believe), but I just bought a PID controller and will retro-fit it to a cheap toaster oven.

Using a reflow hot-air gun is ok, but not ideal.

(JP Roy) #14

Yeah, I have seen a number of these home made reflow ovens over the net but have yet to really need one for myself.

I have tried to solder 28awg solid wire directly to bare ws2812b devices using an old style Weller with very poor success and gave it up.

I can’t imagine trying on the same size device that has 6 pins instead of 4 !!

Now reflow soldering them onto a PCB would definitely be much much easier but the design I had in mind was a 3D contraption (sculpture) made of old CDs (for their reflective coatings) with a few hundred ws2812b.

That simply does not lend itself to any PCB or even strips… :frowning:

(Mike Thornbury) #15

Sounds like “Christmas lights” would be the right tool for the job. Make up an ‘adapter plate’ to glue to the CD and just push the led through, lie a bayonet mounting.

(Mike Thornbury) #16

Or… Make a custom PCB. At under $1 per sq in, it’s not expensive. I just made ten PCBs for a lamp project for $3.30 each, including shipping. The PCB would, in your case, include the mount for the cd and the holes for the wire.

(JP Roy) #17

Hi @Mike_Thornbury ,

I really like your idea of a small custom PCB… never considered it…

I will have to re-examine the feasibility of my ‘CD sculpture with RGB LEDs’ using some custom PCB’s

Thanks!

(Mike Thornbury) #18

@JP_Roy https://oshpark.com/shared_projects/lLsuM1tX

The two holes are 3mm - but I can make them just snug for a 1.5mm grub screw which just catches the edge of the CD, then you don’t need a nut. The CD centre is 15mm.

I’ve had circular PCBs made before and the dimensions are dead on.

(JP Roy) #19

Very nice @Mike_Thornbury

Are you using Eagle CAD ?

(Mike Thornbury) #20

Yes, it’s the only one I know. Do you want the files?