Custom-sized NeoPixel Ring -- How To

[boulderbill]

Is anyone aware of the technique used to arrange the LEDs in a circle for the NeoPixel designs in Eagle?

I'm trying to create a custom-sized NeoPixel ring (32 LEDs - 3.5" OD - 3" ID), but I'm not sure how to perfectly arrange the LEDs in a circle.

Does anyone have experience creating different sized NeoPixel rings?

Thanks!
Bill

[adafruit_support_mike]

The slow-but-easier way is to use the Info tool and set the position/angle of each one individually.

The fast-but-harder way is to write a User Language Program (ULP) that sets all the values as it runs. You'd need to look through the Eagle documentation for information about ULPs to find the necessary pieces.

[boulderbill]

I've created what I think is a working PCB design for a 32 pixel ring.

If anyone out there has a use for this and the ability to validate my design, I'd be super psyched!

Only problem is, it seems like I can't upload Eagle files to the forum. What is the process for sharing designs?

Cheers,
Bill

[adafruit_support_mike]

You can host them on another server, or put them in a zipfile and post that as an attachment.

[boulderbill]

Aha! Here's a zip of them for anyone intrigued enough to check my work.

Thanks!

[adafruit_support_mike]

Looks pretty good overall.

The vias to the ground layer are a bit tight to the signal traces. You might want to move those out toward the edge of the ring, between the pins of each LED. The more clearance you can get between features, the easier the board is to make.

[boulderbill]

Thanks! I will see what I can do to shift those around.

Cheers,
Bill

[boulderbill]

I've searched around the forums and looked into the Eagle files, but I haven't been able to find the specs on the capacitors and resistor on each of the NeoPixel rings. Is that information contained somewhere? Thanks!

[adafruit_support_mike]

Those are debounce capacitors. 100nF is the traditional value, but anything between that and 1uF will work.

[boulderbill]

Thanks Mike. Are you aware of what values are actually used on the NeoPixel rings? I'd like to replicate that circuit exactly on my 32 pixel ring.

Also, how about the resistor?

Thanks again,
Bill

[adafruit_support_mike]

They're 100nF, but the value isn't critical.