Up To 250 NeoPixels

Your NeoPixel strip is directional: it has an IN end and an OUT end. 

You can connect power to either or both ends, but you must connect data (the white wire) to the IN end for the pixels to work properly.

Take a look at your strip. There are arrows pointing from IN to OUT. Find the end with the arrows pointing away (down the strip). You'll make your connections to this end.

Cut a piece of red wire about 2-3 inches long. Use your wire strippers to strip about 1/4" of shielding from both ends.

Strip a little more shielding from the red and black wires coming from your NeoPixel strip's IN end. Twist the red wire you just cut together with the red wire coming from the strip. 

Open the ports on the screw terminal all the way with your screwdriver. Push both red wires into the + side and tighten the screw. Push one black wire into the - side and tighten.

Tug on the wires to make sure you have a very secure connection.

Connect the remaining red, white, and black wires to the Circuit Playground as shown:

  • Red to VOUT
  • White to A1
  • Black to GND

You can screw them into place with your bolt-on kit, or solder them with your soldering iron if you prefer. Either way, be sure you have a nice tight metal-on-metal connection with no stray wires promiscuously touching neighboring pads.

More Than 250 NeoPixels

After around 250 pixels the 4A power supply attached to one end of the strip will become insufficient. The copper pads that pass power and data along have a small amount of resistance, and that resistance adds up after a while. What this means is that each subsequent pixel gets a little less power until the ones at the very end are dim. This is called "brown-out." 

In this photo I have my power connected to just one end of a 4 meter strip of lights, with the lights on full brigthness. You can see how the outside of the spool is an almost bluish white, and the inside of the reel gets increasingly brown in color. This is how you know you need more power.

Why This Happens

There are actually 3 LEDs inside each NeoPixel: a green, red, and blue LED. If you turn your strip to show bright white, the NeoPixel strip "builds" this color by turning on all 3 LEDs as bright as they will go. This means that full-bright white uses three times the power that full-bright red or blue or green uses. 

My single power connection works fine if I make all the lights blue. But for a bedroom light, I want the ability to turn up the lights to a bright white, in case I need to vacuum, or wake somebody up, or something. Adding power at the other end of the strip is a great way to do this. 

For even larger installations, you can connect power to the middle of the strip as well. This is called "injecting" power. It's a good idea to inject power every 250 lights or so if you want the option of a steady bright white light.

Adafruit helpfully attaches wires to both end of the NeoPixel strips, so it's easy to add a second screw terminal and a power splitter to the other end, in the same fashion as above. 

You will also want to upgrade to a beefier 10A power supply if you have a whole lot of lights. Get a splitter and an extension cable or two as well if the two ends of your strip aren't within easy reach of each other.

Do NOT connect the two different ends to two different outlets using two different power supplies. This will cause all kinds of problems and can damage your board.


Q: My lights are flickering on and off with some of the animations. How do I fix this?

A. You may have a less-than-optimal data wire connection. Try readjusting your bolt and nut so there's more metal-on-metal connection, or upgrade to a soldered connection which will pass the data much more cleanly.

If that doesn't fix it, try using a different screw terminal. Sometimes the internal workings don't line up as well as they should and it's not that uncommon to get a "bad" one.

Q: My lights come on for a minute then click off again and my board resets. What's going on?

A. You may have insufficient power. Try using a larger 10A power supply and connecting to both ends of the strip. Or try turning the brightness down in the code. One more thing to try is to temporarily "shorten" your LED strip in the code (set NUM_LEDS to 10 or 20 instead of your full count) to see if that fixes things.

Q: I'm getting really fast flickering with inconsistent color. 

A: Your ground connection is probably loose. These screw terminals can be really fiddly and sometimes don't give you a great connection. Try reconnecting the wires, making sure you've got enough shielding stripped off before shoving the end into the port.

Q: My lights aren't lighting up at all.

A: Are there lights on the face of your Circuit Playground? If the board is getting power but the lights aren't coming on, it's either a problem with the wire connections coming from the strip, or a problem with the code. Check to be sure you've connected to the correct pads (A1, VOUT, and G). Double check to be sure you have all the correct library files installed, and try re-uploading your code.

If the board is not getting power either, it may be a problem with your power supply. Check your red (power) wire connection at the screw terminal.

Q: I've got another problem I need help with. Where can I get support?

A: We've got lots more troubleshooting ideas on this page. Adafruit also has a Discord Community where there are experts available to help you with your build. Come join our community! 

This guide was first published on Sep 29, 2020. It was last updated on 2023-12-06 13:55:45 -0500.

This page (Electronics Assembly) was last updated on Sep 23, 2020.

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