Use a NeoPixel Strand

Another option for lighting up your masking tape hand is a NeoPixel LED Dots Strand. It consists of 20 individually addressable LEDs that you can program just like the onboard NeoPixels using MakeCode. It can run the same animations as the onboard NeoPixels, or create your own lighting pattens!

Unlike the NeoPixel LED Strip that comes with alligator clips for easy attachment to the pins, the strand is flexible enough to let you (gently) bend it to fit inside the fingers of your hand.

However, you'll need to do a little prep work first to connect it to the CPX. Here's how:

Cut Off One of the Connectors

The NeoPixel LED Dots Strand has connectors on either end. The male connector (on the left in these photos) fits inside the female connector (on the right). They make it possible to join multiple strands together for extra-long builds.

For this project, you will cut off one connector and attach it semi-permanently to the CPX. Then you'll be able to plug the other end in when needed and remove it when you're done.

To figure out which end to cut off, examine the back of the LED Dots. You will see markings that show which way data from the microcontroller flows through the strand. You will cut off the end where the data is flowing OUT of the NeoPixel.

Sometimes the markings look like arrows. In this example, the Dots are marked with the words "IN" and "OUT." The print is tiny, so look carefully!

On the strand shown here, the OUT end happens to have the male connector. But it can differ, so always check!

Take wirecutters, or use the blade part of the wire stripper, and cut off the connector at the OUT end of the strand.

Leave a short bit of wire at the end of the last Dot, just in case.

Also cut off the two wire ends on the other connector. You will not need them for this project.

To avoid a short circuit on the strand, make sure metal wires are not sticking out from the clear plastic insulation on the remaining ends.  You can cover the ends on the strand with electrical tape for extra protection.

Attach the Connector Wires to the CPX

Take the cut-off end and separate the three wires attached to the connector. You will connect each wire to pins on the CPX, but first you have to expose the metal wire inside the clear plastic insulation.

To do that, use the wire stripper to strip about 1/4 inch of insulation from the end.

Gently clamp the wire stripper around the insulation in the notch that fits best. Squeeze just tight enough to cut through the insulation but not the metal wire.

Then pull the wire stripper towards the end, hopefully pulling the insulation off with it. Do the same with the remaining wires.

Since the exposed metal wire is stranded and tends to unravel, take the end of each wire and twist it to keep it together before the next step.

You will use nuts and bolts to attach the three wires on the connector to the CPX. They go in this order:

  • The red wire supplies power to the LEDs and the electronics in the Dots. It is connected to the Vout or 3.3V power pads. (The "V" stands for "voltage.")
  • The middle wire carries data -- the instructions you send to the LEDs to tell them what to do.
  • The outside wire on the other side is connected to one of the GND (ground) pads to complete the circuit.

For this example, the red wire will be connected to the 3.3V pad next to the USB jack, the middle wire will be connected to Pin A1, and the ground wire will be connected to the GND pad in between them.

Insert a bolt into each of the holes you are using from the top on the CPX board. Screw a nut on the end of the bolt underneath the board. Leave it loose for now.

Take the first wire and curve it around the screwdriver. Then hook the curved wire around the bolt, next to the nut on the underside of the board.

Use the screwdriver and your fingers to tighten the nut and bolt to hold the wire in place.

If there are any loose strands of wire sticking out, be sure to tuck them in so they don't cause a short circuit!

Do the same with the remaining wires.

Connect the Strand of Lights

The only thing left to do is join the two connectors.

Now the strand is hooked up to the CPX and you are ready to code it with MakeCode!

This guide was first published on Oct 28, 2019. It was last updated on Oct 28, 2019. This page (Use a NeoPixel Strand) was last updated on Jan 11, 2020.