Introduction: WiFi-Linked Twin Dolls

Picture of WiFi-Linked Twin Dolls

My project is a pair of brothers that can sense and reciprocate each other's feelings via WiFi. This means that they can always communicate, no matter how far they are apart.

If one of the brothers is touched, he expresses his feelings in the form of a light or a vibrate. Since they're inputs for feed into an Adafruit IO page, however, those feelings get reci-procated on the other doll. In this way, whatever you do to one doll is felt by the other.

These little guys can be shared between any pair of people who share a bond like the brothers do, that way, no matter how near or far, you can always let them know you're thinking of them.

Step 1: Supplies & Tools

Picture of Supplies & Tools

Here's everything you'll need to start your journey:


• single-strand insulated wiring (get different colors)

• 100-1K Ohm resistor

• NPN transistor (PN2222)

• heat shrink tubing

• breadboard

• prototyping wires

• solderless breadboard

• perma-proto board

• lipoly battery

• usb cable

• adafruit feather huzzah

• flesh-colored felt (at least 1 yard)

• cotton jersey fabric (at least 1 yard)

• cotton twill fabric (at least 1 yard)

• threadsewing needle(s)

• eye-colored buttons

• hair-colored yarn

• 1 red LED

• 1 blue LED

• 2 small motors (NOT big ones, they won't work)

• polyester or wool fill fiber

(keep in mind, you'll need an extra set of everything above for each additional doll you create)


• pencil

• compass

• ruler

• cutting mat

• wire strippers

• scissors

• sewing machine

• flush wire snips

• solder

• soldering iron

• adjustable desk lamp

• third hand tool

• heat gun or lightertape

Step 2: Set Up Your Adafruit IO Account

Picture of Set Up Your Adafruit IO Account

In order for your dolls to speak to one another, you'll have to set up an account on Adafruit IO. You can follow navigate here and follow the prompts to create your profile.

Once your profile is created, navigate to the Feeds tab and create a new tab. Label it "Command". This is where your Huzzah's will send the data from the push button inputs you create.

Step 3: Write Your Code

Picture of Write Your Code

The dolls use code written on Arduino for the Adafruit Feather Huzzah. You'll notice that there are 3 inputs for the left hand LED, right hand LED, and chest vibrator motor.

On the config.h tab of the code, make sure to input your IO name and key as well as your local WIFI name and password. Be careful with this since Arduino only recognizes usernames and passwords typed EXACTLY the way they're written.

Step 4: Wire Your Dolls

Picture of Wire Your Dolls

Take care to wire your dolls according to the images and diagram above. For now, wire then onto your solder less breadboard and use the prototyping wires. For more exact instructions, have a look at the code to see which wires control which elements. Each time you set up a new element, make sure to test it to make sure it works. If it doesn't, here are some troubleshooting steps I used:

• Are the wires placed in the correct pin as per the code?

• Are the wires sent to power and ground properly?

• Are you on the right WIFI? Is your WIFI on and functioning?

• Is your battery charged?

• Are your wires soldered securely and/or connected?

• Is your code loaded?

• If you've made a change in the code, have you reflected it in the wiring?

• Have you tested all your input and output components to make sure they're all working?

Step 5: Sew Your Forms

Picture of Sew Your Forms

• Using the file attached, cut out the pattern and use as a stencil to trace the doll's body onto the flesh-colored felt. Remember, once sewed and stuffed, it will appear thinner and smaller than when layed out flat, so size accordingly.

• For the hands and feet, cut 3x3 inch squares.

• For the head cut 2 U shapes with a 5 inch diameter. These will become the head.

• To sew the body, fold in half and sew from the outside edge of the leg up to the underarms and around to the bottom edge of the wrist. Repeat on the other side. After, sew from the inside edge of the leg around the crotch to the other inside leg.

• As per your pattern, cut a shallow moon-shaped arc into the top of the doll where the head will go.

• To sew the feet, ball up a tangerine-sized amount of fill fiber, wrap a square around it, hog tie it, and tie shut. Stuff the end into the foot hole, and with a needle and thread, sew the foot to the body around the perimeter where they meet. Hold off on the hands and head, though, we'll be putting wiring in those in a sec.

Step 6: Prep Your Electronics for the Doll

Picture of Prep Your Electronics for the Doll

Now it's time to make all those connections you made on your breadboard permanent. Take your solderless breadboard, and, one element at a time, transfer your wiring over to the perma proto board and solder. I found that starting with the vibrator assembly helped. I then soldered the Huzzah, and finished with both led assemblies.

Attach your vibrator button to a piece of cardboard or any firm plate about the size of your doll's chest. Once the wiring is attached, soldered, heat shrank, and tested, place this in the chest, and test.

Wrap your LED and button assemblies for each hand in a ball of fill just like the feet you did a minute ago. Hog tie, and sew like before, taking care to feed the wiring through the arms ant out the neck.

At this point, your doll's neck will look like some robot toy nightmare that Sid from Toy Story might have created. Make sure to mark your wires with sharpies and create a legend so you don't get them mixed up and soldered incorrectly.

Step 7: Sew & Test

Picture of Sew & Test

Once you've got everything working, go ahead and TEST, then sew on the head, and eyes. To help tell my dolls apart, I gave one of them brown eyes and the other blue. You may want to do something similar.

Finally, make sure you give them both names. Everyone needs a name.


Step 8:


RossH43 (author)2017-12-20

Thats so awesome andre!

Swansong (author)2017-12-19

That's a cute gift idea, especially for a kid whose parents have to be gone often :)

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