You can either choose the 3d printed case or the laser cut case. I recommend the 3d printed case since it's a very slight mod of the excellent case from the Neopixel LED Heart Necklace tutorial, and it allows access to the reset button. 

If you want something a bit smaller and compact though, the laser cut case is provided here as well (it's slimmer in width, but thicker in depth).

3D printed hex case

Carefully slot the ItsyBitsy, LiPo backpack and slide switch as shown -- the model will have dedicated structures to support these parts.

Align the microB usb port to the remaining hole to the left of the switch. Secure it using some double sided foam tape, and make sure that it's right up against the edge of the case. Test that the necklace's microB plug will fit into the plug through the case hole and adjust accordingly.

Connect the battery to the LiPo backpack and place on top of the ItsyBitsy as shown. You may want to tuck it under the wires. There should be no tape needed to secure this battery. 

Nudge the wires away from the RESET button before putting on the case cover, making sure to align the RESET button with the button extender.

Optionally, add another brass shape to this case for extra bling.

Laser cut rectangular case

This case is made up of 4 different types of panels, with finger joints that slot into each other:

  1. Top/bottom panels
  2. Side panels
  3. Necklace port panel
  4. Power and charging port panel

Add thin tape to LiPo battery and foam tape to LiPo backpack


Then, with the bottom panel and one of the side panels attached perpendicularly, place the battery and the LiPo backpack to the bottom panel as shown in the photo.

The thin tape is needed for the battery so that the ItsyBitsy can fit on top of it and align with Panel #4 (as referenced above).

Fit the switch in the appropriate cutout in Panel #4 and fit that panel with the rest of the case.

Secure the USB MicroB port in place


Use foam tape to secure the microB port as shown in the photo. The edge of the port should be as close as possible to the inner edges of the finger joints.

Then, attach Panel #3 (necklace port panel), and make sure that the microB port is aligned with the cutout.

Place the ItsyBitsy on top of the battery


Cut some foam tape to fit in the flat areas on the bottom of the board. The foam tape should be thick enough to allow the ItsyBitsy to lay flat. The amount of tape shown in the photo should provide enough resistance when inserting a micro USB plug into the board.

Secure the ItsyBitsy on top of the battery and make sure to align the edge of the ItsyBitsy right up against the panel, centering the microUSB port with the cutout on the panel.

Close up the case


Once you're happy with how everything is laid out, you can use super glue or any other appropriate glue on the finger joints to solidify the case.

Secure and glue the last top panel, and if desired, add a bit of flair with another brass shape. The contrast of brass and black here is simply beautiful!

And that's it! You can now light up the night (or day) with your very own modern geometric LED matrix necklace. Ask the necklace a question, touch for the answer, and may the Fortunes smile upon you.

Below is a photo of the combination of the 3D printed hex case and the laser cut pendant frame, which is definitely my fave combo. Since the parts of this project is quite modular, there's lots of room for customization, and with CircuitPython it's quite easy to change the LED animations. Have fun modifying this project so that it suits your own style!

This guide was first published on Dec 22, 2020. It was last updated on Jul 19, 2024.

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

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