Robot Mask With Neopixel Eyes, IPhone Mouth, and Voice Changer




This year for Halloween we decided to make a robot mask for our oldest son. There are a few different electronic components that work together to make the final mask. We used neopixel rings and an arduino to control the eyes, an old iPhone worked as the mouth, and we took apart a cheap voice changer toy to add some more fun.

We are entering this in a few different contests, so if you enjoy this instructable, please vote for it.

Step 1: The Box (Head)

To make the box I used silver foam core board I found at Hobby Lobby. This is not the only way to do it though, as this added cost and complexity to the build that may not be necessary. You could easily use an existing cardboard box that you paint or cover with metallic tape. In any case, I will detail my process, but know that you may want to chose a different path.

To make the box, I used the Xacto 45 degree cutter. Here is a video of how that cutter works:

Full disclosure, I used a cheap knockoff no name brand I found on ebay for ~$6 (the actual cutter is crazy expensive). By watching the video you can see how to make the various types of cuts with this knife.

I didn't waste a lot of time measuring anything exact, I basically took a sheet of standard size paper (8.5" x 11") and used that to mark an 11" square on the foam core board. Ultimately you will need 5 sides cut (all around your head and one for on top). The 4 that go around your head need all of the sides EXCEPT 1 cut at 45 degree angles. The top piece need ALL of the sides cut with a 45 degree angle. I did this by tracing all of the side pieces along the bottom of the foamcore board so that I could leave that bottom edge as a straight angle.

Once I had the lines traced on the foam core board, I laid a flat edge metal ruler down and ran the 45 degree blade down the board (I used a self healing mat under the board). I took multiple passes making sure the piece was completely cut before moving my straight edge.

Once I had all of the parts cut out, I simple glued it together with superglue. I used blue painters tape to lay the 2 mating edges together, applied a thin coat of super glue, and then folded the edges together and let the tape hold them in place as it dried. The blue tape ended up taking a bit of the silver off a few spots of the mask, but I didn't care too much (but you may want to be careful when you do it if you don't want any torn spots).

Once I had it all assembled and dried, I took a tile sponge (any suitable foam would work fine) and hot glued it to the roof of the mask along with a length of elastic. This will cushion my sons head and keep the mask in place while he is wearing it. I had him come out to the garage and try it on for size just to make sure it fit before I went any further. Next

Step 2: The Eyes

For the eyes I used 2 16 Neopixel rings in some plumbing fittings I found at Home Depot. I chose some ABS 1 1/2" - 2" coupler reducers. They were a few bucks and they fit the neo pixel rings perfectly on the smaller end. I spray painted the outside of the couplers with silver spray paint to add to the robot-y-ness, and then started on wiring up the neopixel rings to my arduino.

I used a Arduino Pro Mini, but pretty much any arduino would work (I almost used a spare lilypad I had laying around, but ended up using that for a different project that will make a future instructable). These little boards are cheap and great. Since they are so inexspensive, you can throw them in a project and not worry whether you ever get it out (I found mine on ebay for about $2.50 each shipped).

I won't bother writing up too much on the wiring since Adafruit has done a fantastic job of this already (no sense in reinventing the wheel), so check out their guide located at and their video I will post below:

Their sample code they have was perfect for this project (the rainbow eyes looking around and blinking). I chose to use a 3xAA battery pack to power mine since it would last longer and I had the parts in my extra parts bin. The adafruit guide shows a few different options for power, choose whatever will work best in your mask (nice thing about the robot mask is there is plenty of room inside the head for electronics).

Once I had the neopixels wired up and working, I called my son back in, and then took my tape measure and while he was standing up tall, I measured from the ground to the middle of his eyes. Then I put the foamcore box on his head, and using that measurement, marked the box where the eyes needed to go.

Once I had that mark, I place the 2 plumbing rings on the box at centered over the eye mark, and traced the 2 outlines of the smaller side of the rings. Using a regular xacto knife, I then cut out the holes from the circles traced. After they were cut, I squeezed the 2 couplers into the holes and put a bead of hot glue around the inside to hold them in place.

Once the glue dried, I slipped the neopixels in (from the back or inside the mask) and put them in place (making sure to pay attention to orientation of each ring so that the eye placement matched up on both rings). Then I shot a little more hot glue on each ring to hold it in place.

I grabbed a couple of cable zip ties, and then I took all of the wires from the neopixel rings and brought them out as flat as possible around the outside of the couplers. Then I zip tied them in place to help with stress relief, and also to help hold the couplers in place without slipping out of the holes. I then covered it with some more hot glue and pressed the arduino, wires, and battery pack down with lots of hot glue to help secure it all. Since I wasn't worried about other people seeing the inside, I went to town with the hot glue (I figured it would help with the inevitable moisture that would accumulate in the mask from breathing too).

I tried it on and was very happy to find that the neopixels did not blind the mask wearer at all. I was worried that some of the light would come back in the mask and make it impossible to see out of the mask, but it's fine and does not bother your eyes at all. Peripheral vision is still very limited, but blinding light is not a problem.

Step 3: The Mouth

The mouth was very easy. We had an old iPhone 3GS sitting in a drawer collecting dust, so we decided to use that with an app called MouthOff ( I'm pretty sure any smart phone would work for this (I don't know if the androids have the same app, but they probably would have something similar). I measured the screen of my old iPhone (it was 2" x 3") and then made a 2" x 3" square in my image editing software (I used Illustrator, but any would do), and then printed it out on card stock.

After I printed it out, I cut out the square, and then used that to trace the box on the mask where I wanted the mouth to be. I just lightly traced around the cardstock with a pencil, and then cut out the rectangle with a regular xacto knife.

I had an old case for the phone, so I decided to slip the phone into the case, and then hot glue the case to the mask. You won't have access to your home buttom, but it's not really needed if all you're doing is starting the MouthOff program. I set the phone to never go to sleep (so it just stays on all the time) and then added the MouthOff app to the front screen (I did this before I glued it in place). Now I just have to use the power switch on the top of the phone to turn the phone on or off and launch the app with the touch screen.

Step 4: The Voice Changer

I added the voice changer as a little added fun to the mask. The one we bought had 4 different voice settings on it (including one labeled "Robot") but they all sounded pretty electronic and robot-y sounding.

These things run off of a 12 volt battery (to power the speaker I'm guessing). So I decided to break out my dremel tool with a cutting wheel and cut the battery compartment out of the toy. Once I had that cut out, I found an extra switch I had laying around in my parts bucket and wired the switch in place of the 2 contacts that were used with the old trigger. This way I was able to turn the voice changer on and leave it on without pushing a button.

Once I had all of that working, I started to hot glue it all in place. I started with the microphone, placing it right on the phone case where the mouth would be. Then the rest of the components were placed relative to the wire length that was attaching them to each other. The battery got mounted a little above the phone, the board with the voice setting switch was placed just beside the microphone, and then speaker was first placed right next to the phone, BUT before the glue dried completely, I realized that it was right in the way of the phones charging port. I quick pulled the speaker up before the glue set completely and then had to find a new spot for it.

Since the wires were fairly short, I ended up having to add some extension wires to the speaker, and then place the speaker on the wall facing out the side of the mask. I was worried this might make the voice changing sound too odd (coming out the side instead of the front) but it was fine. You can still hear the mask wearers voice, but the added electronic voice just gives it a little extra kick.

Step 5: Balancing the Mask

With all of the components (and probably a pound of hot glue) sitting on the front of the mask, it made it so the mask had a tendency to slip forward. To help balance this out, I grabbed a few large nuts from my parts bin and hot glued them to the back of the mask as a counter weight. Anything work work here, you don't need to go buy specific nuts like the ones I used. Anything heavyish should be usable to help balance it out. I taped the nuts on first and tested it to see if ti was enough before I glued it.

I then found some extra foam my wife had purchased for another project and cut that up a bit to fit in the mask for a better fit. I put a piece along the back of the mask to cushion the back of the wearers head, and then a strip along the forehead area to stop the mask from bumping the wearers nose. I found with added foam, I don't need to wear the elastic to have it hold in place, but my 7 year old son still needed the elastic as his head is a little smaller.

Step 6: Action Shots

The mask was a hit. Everyone loved it and stopped to ask how it was made and see it in action. We had my son wear a cheap grey sweat suit to go along with it (which gave it that cheesy 80s robot feel and was really fun). As an added bonus, the eyes were so bright that when we were out trick or treating after dark with the kids, he lit up the way between houses nicely.

It was a great project and turned out better than we hoped. If you enjoyed this instructable, please vote for us!



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    10 Discussions


    3 years ago

    Was he able to actually see or no? I was thinking about making something like this for a project. Yours looks amazing.

    1 reply

    Reply 3 years ago

    Yes, you can see out of the mask great. I thought the neo pixels would blind him, but since they face out, they didn't affect his vision at all. It actually kind of helped light the way on Halloween night when we were out trick or treating with all the kids (bonus).


    Reply 4 years ago

    it s great, funny, and nice ! i love the multicolor eyes and the idea of including the voice changer. thanks for sharing, great job ;)


    Reply 4 years ago on Introduction

    Thanks for the comment. It was tons of fun to make and my son loved wearing it.


    4 years ago on Introduction

    It's so awesome! My son always wants me to build him a robot...this would be perfect! :) Great job Melarky!

    1 reply

    Reply 4 years ago on Introduction

    Check out the bristle bot ( is a good video, they probably have an instructable for it too I bet). After you finish that, the beetle bot ( is a great robot to build with pretty easy to source parts. Our boys have loved those projects!