Monster Pajamas

Introduction: Monster Pajamas

These stuffed animal pajamas were designed to help your child not be afraid of the dark! They have a night light and a sound module where you can record any song they like, as well as voice recordings of you or other loved ones speaking or singing.

Step 1: Supplies & Tools

Stuffed Animal
Gemma MO
Neopixel Ring 16
Sound Module
Metal Snaps
Battery Pack
2 Coin Cell Batteries

Hot Glue Gun
Soldering Iron
USB to Micro cord
Wire Strippers

Step 2: Solder Gemma MO to Neopixel Ring

Use this circuit diagram to solder connections between the Gemma MO and the NeoPixel ring. (From Les Pounder at

Use this link for instructions on how to solder.

Step 3: Code the Gemma MO and Download a Song for the Sound Module

Use the USB to Micro cord to plug your Gemma MO into the computer.

Use these instructions on how to get started. I used circuitpython, but you can also use arduino.

I used the text editor Mu, and it worked wonderfully, because it auto saves to the circuit board and immediately starts enacting new code once you click save. Here’s a link to a page about how to use Mu.

The code I used to program the lights is in the image above. (From Les Pounder at

. If you want to change the color of the night light, just change the RGB values. (255, 0, 0) will give you red, (0, 255, 0) will give you green, and (0, 0, 255) will be blue. You can use any combination of the three values to choose a custom color. NOTE: this code does not change color or flash. There is an initial animation sequence while the light turns on, and then the light just stays on.

Make sure to test your Gemma to make sure the lights turn on!

The sound module comes with instructions on how to download a voice recording or a song to your sound module. Basically you use the included audio plug to connect the module with your phone or tablet, press the record button on the module, and then play from your device whatever song or voice recording you want. The sound module only has 2 minutes of memory. When you’re done recording, press the record button again. Make sure to test the sound module to make sure your song recorded correctly.

Step 4: Make the Pajama Pockets

You want to be able to wash these pajamas, so we’re going to make pockets inside the pajamas for the electronic parts to sit in. You can use whatever color of fabric you want or have, since it won’t be seen from the outside of the pajamas. The black fabric shown here was from the scrap bin in the fabric section of my grocery store.

We’ll need two holes in the pajamas for the light ring and the sound module button. Where you cut the holes will determine where your pockets are. Use the neopixel ring to draw a circle on the pajamas where you want the night light, and cut it out. Cut out a small hole where you want the sound module button to be.

Cut pockets that are big enough to hold the inserts, and make sure to leave at least a half inch margin on each edge. You’ll need room for glue and snaps later.

Glue a corner or two of the pocket in place, then make sure the insert fits before glueing the rest of the seams.

With the inserts in the pockets, decide where your metal snaps will go. These will be used to close the pockets once the inserts are inside. You can hot glue or sew these to the fabric. Sewing is more secure, but takes more time.

Turn your pajamas over and make sure your pockets are not visible from the outside.

Step 5: Make the Electronic Inserts

You want to be able to wash these pajamas, so we’re going to hot glue the electronic pieces to pieces of craft foam so we can easily slide them in and out of inside pockets on the pajamas.

Cut 2 pieces of foam, one for the sound module and one for the lights, circuit board, and battery.

The piece for the sound module can be the same size as the module. My sound module had a sticker backing, so I was able to just remove the backing and stick it directly to the foam. If yours does not have a sticker, do not use hot glue to adhere it. It will melt the soft plastic of the sound module. The button should also have a sticker back. Remove it and stick the button wherever you want on the sound module.

The piece of foam for the lights will need to fit between the lights and Gemma, and have a place to glue the battery pack. If your foam fits snugly, there is no need to glue the Gemma or the lights, but make sure you glue the battery pack. I added another dot of glue to keep the wires closer, but this is not absolutely necessary. I glued the fabric I cut out of the pajamas on the previous step onto the foam in the middle of the light ring, so that the foam is not visible, and it looks more like a part of the pajamas.

Step 6: Assemble Your Monster Pajamas

Now it’s time to put the electronic inserts into the pockets, close the snaps, and put the pajamas on the stuffed animal!

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    3 years ago

    This is a super cute project!