NeoPixel PSI – Designing the PCBs

Something I’ve been meaning to do for a while was look at how to do a PCB with SMD layout that is now offered by a few of the cheap chinese fab houses.

A bit ago I did some reasonably cheap PSIs for R2 using off the shelf components, and even added the support into the ReelTwo library. However, these still weren’t what I wanted. I’ve used the VADER PSI boards in the past, but the source was closed and I had a few failures with them.

So, last week I had the motivation to take a look at doing a simple PSI board using WS2812 RGB LEDs, commonly referred to as NeoPixels.

I decided to also give EasyEDA a try, seeing as it is a schematic and board layout system that is provided by my usual PCB manufacturer, JLCPCB.

Not only has it got a very quick learning curve, it also has a great library of parts and is well integrated into the whole manufacturing process. In fact, it only took me a couple of hours to get to grip with it and get a first pass of a board layout done!

With a few clicks, I had the correct parts selected and a Pick and Place file downloaded, along with the BOM. I took these over to the JLCPCB site and uploaded them to see what the cost was. With a minimum of 5 boards, it came out to about £20, and with a nice £5 off coupon I figured I just give it a go.

My first attempt had some issues with ambiguous layouts and the wrong components selected in the BOM, but the customer service was very helpful and cancelled the order so I could try again. My second attempt also let me put a nice R2 Builders logo on the back of the board. Thankfully it went a lot smoother this time and I soon had an order in and processing!

Now all I had to do was wait.

A pleasant surprise was that it only took a little over a week, and 5 nice new PSI boards, fully populated with 21 WS2812 LEDs dropped through my door. All that was needed was to solder a 3 pin header onto them.