NeoPixel rings and pixels have solder holes spaced out along the circumference of the ring. First we'll solder one ring, then we'll talk about how to chain them together.
Step 1: Identify Your Solder Pads
- 5V (or sometimes +) -- larger rings have two connections, smaller rings have one
- G (or sometimes GND) -- larger rings have two connections, smaller rings have one
- Data IN & Data OUT
Step 2: Prepare your Wires
Unspool and cut three wires of about equal length in red, black, and white. These will connect to your microcontroller, so think about how far you want to place your controller from the pixel strip and before cutting them to length.
Your data signal will start to degrade if the wires are more than about 3 feet long, so keep them shorter than that.
Use your wire strippers to strip about 1/8" of shielding off the end of the wires -- enough to make it all the way through the hole and out the other side.
Give the exposed wires a twist with your fingers to make sure no tiny little strands are poking out. Make it as neat and tidy as you can. Messy wires are not your friend.
Step 3: Insert Wires
Bend the tips of the stripped wires 90 degrees. Place your NeoPixel ring face down so you can see the markings clearly. Slip the wires through the ring from the front to the back: red to 5V, white to Data IN and black to GND. Make sure all the little strands make it through the holes.
Step 4: Solder
Turn on your soldering iron and wait until it's fully heated. If it has a temperature gauge, set it to 750 degrees. Otherwise, just wait about 3-5 minutes so you can strike while the iron is hot.
While you're waiting, get the little sponge in your soldering iron stand wet so you can clean off the tip of your iron. Go ahead and clean it off now, once your iron is hot. It's easier to solder with a clean iron.
Unspool a bit of solder. Touch the tip of the soldering iron to the copper pad and also to the wire at the same time. Wait a couple seconds for everything to heat up. Then, touch the solder to the wire and copper pad. The solder will start to melt and flow along the wire and pad, creating a shiny little "hershey's kiss" shaped blob.
Once this happens, lift your soldering iron away and clean off the tip with the sponge on your stand.
Repeat with the remaining wires.
If your solder blob is really tall, it's fine to trim it down a little bit with your flush cutters.
You may look at this and think it looks backwards -- won't the wires be showing on the front of the project if we hook it up front-to-back?
It's true that the wires are slightly more visible this way, but since the spacing is so tight it's likely that you could damage the pixels if you try to squeeze the soldering iron between them on the front of the ring. Once the lights are on the wires won't be noticeable! So do it front-to-back if you can.
Step 5: Test Your Ring
Grab your alligator clips and your testing microcontroller. Clip the red wire to VOUT, the white wire to A1 and the black wire to G. Make sure the alligator clips are not touching each other and that your connections are firm.
If you haven't done so yet, upload some test code to your microcontroller. Here's some test code you can use with the Circuit Playground Express or a Gemma M0 that will run a rainbow along your ring if you attach it to pin A1.
- Download the appropriate UF2 file
- Plug your microcontroller into your computer with a good USB cable. The lights on the face will turn green. If they don't, click or double-click the tiny "reset" button in the center of the board until they do.
- A drive will appear on your computer called CPLAYBOOT (for Circuit Playground) or GEMMABOOT (for Gemma M0). Drag the file you downloaded onto this drive. You're done!
If you're having trouble, head over to the Circuit Playground guide to get things working.
Adding More Rings
Chaining multiple rings together is fairly easy with the larger rings that have two 5V and two GND pins. Just solder another red and black wire into each of those holes and attach them to the corresponding holes in the next ring. Solder a white wire into the Data OUT hole. Data OUT from the first ring will attach to Data IN on the next ring in the series, and so on.