NeoPixel Connections

Data Flow Direction

NeoPixel strips have an "in" end and an "out" end. There are usually arrows marked on the strip showing you which is which. Power can connect from either end but data MUST flow from IN to OUT. We've got a whole guide on connecting NeoPixels - check it out here.

For the side-light LEDs, instead of an arrow, the pads are marked with DI on one side and D0 on the other. Line up the lights so DI is closer to you as the strip is going away from you.

Find the IN end of your first strip. Cut off the connector and strip some shielding from a red, black, and white wire.

Use the bolt-on kit or solder the wires as shown:

  • Red to VOUT
  • White to A1
  • Black to G

Power Connection

We're using a screw terminal to connect the power supply. For projects with a lot of LEDs, it's always good practice to connect the power midway through your LED strip. This way the power flows evenly to all parts of your project, and you won't get brown-outs. This will also protect your Circuit Playground from drawing too much power.

Find the OUT end of your first strip. Plug the connector (female, in my case) into the IN end of the second strip to daisy-chain them together.

Strip a bit of shielding from the loose red and black wires near this connector. Twist the red wires together and push the ends into the + hole on your screw terminal.

If you're adding the capacitive touch board, cut an additional black wire and twist it together with your two NeoPixel black wires. 

Insert the black wires into the - hole on the screw terminal. Tighten both screws until the wires won't pull out when you tug on them.

If you're doing the lights-only version of this project, you're done -- that's all the wiring you need to do. To add sound effects and interactivity, read on.

Capacitive Touch Board Connections

Solder your MPR121 board to your Circuit Playground as shown:

  • 3.3V to VIN (red wire)
  • G to G (black wire)
  • SCL to SCL (yellow wire)
  • SDA to SDA (green wire)

Find the third black wire you connected to your screw terminal and solder it into the remaining G pin on your MPR121.

That's it for now. We'll solder the wires to the individual bottles into pads 1-11 later -- it's much easier to build the bottles with loose wires and hook them up to the MPR121 board at the end.

Speaker Connections

Solder or screw the speaker to the Circuit Playground as shown:

  • AUDIO to SIGNAL (yellow wire)
  • 3.3V to POWER (red wire)
  • G to GND (black wire)

If you're using two speakers, plug the 3-pin JST cable into the JST port on both speakers to daisy-chain them.

Once you've uploaded your code, plug your power supply into your screw terminal and test it out. Touch the pins on the MPR121 board. If all goes well, you'll hear different tones play and see different sections of your light strip come on. Woo hoo! Time to build the castle.


If it's not working, here are a few things to try.

If the lights aren't coming on:

  1. Have you uploaded your code correctly? Head back to the Software page and double check you've uploaded all the files. If even one is missing the code will hang.
  2. Did you solder to the IN end of the strip or get that mixed up? The markings can be confusing. If you're hearing sounds but not seeing lights, this might be your problem.
  3. Check to be sure you've got the NeoPixel strip data line wired to A1.
  4. Try re-connecting to the screw terminal. These things are notoriously twitchy.

If you're not hearing sound:

  1. Double check your wiring connections and be sure they match the wiring diagram.
  2. Try plugging in just one speaker. Simplifying things usually helps with troubleshooting.
  3. Be sure you've got the audio files uploaded along with the code.

For more troubleshooting ideas, head over to the Circuit Playground Bluefruit guide. Try uploading some test code to test your NeoPixel strip and your speakers individually.

This guide was first published on Jul 15, 2020. It was last updated on Jun 17, 2024.

This page (Electronics Assembly) was last updated on Mar 08, 2024.

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