I created the Possessed Baby as a Halloween prop assignment for my Technology and Design Integration Class at Horace Greeley High School, with the help of Jess Cristino, who's a teacher's assistant in my class. Our goal was to design and develop a doll that would catch people's attention when noticed and hopefully scare them as soon as they held its hand. While this doll certainly isn't your typical cute and smiley baby doll, I can assure you that it's a unique and scary twist on what was once just a plain old motionless toy.
Step 1: The Creative Process
Before starting any project, I like to sketch out some of my ideas to plan how they might look, what tools and materials I will needs, and what skills I will need to learn in order to execute the idea. The Possessed Baby idea was actually the third sketch I designed. I chose to go with this one because it was my most creative idea, and the process would involve learning some new skills that I knew could be helpful for future projects.
Step 2: The Materials
For this project, I needed:
1. a baby doll
2. an Arduino
3. I computer with the Arduino Program on it
4. an Arduino sound module
5. a motor
6. two RGB LED modules
7. two LEDs
8. an Arduino button module
9. hot glue and a hot glue gun
10. rubber bands
11. about one square foot on 1-inch thick wood
12. a thick piece of white paper, about 4 inches by 6 inches
13. a sharpie
14. a saw
15. a drill
16. two small nails
18. electrical tape
19. a barrel jack cord that can connect to an outlet
Step 3: Setting Up the Arduino
I began the process of bringing my sketch to life by setting up the Arduino. I attached each module to a different port on my Arduino.
The sound module was put into D2. The button module was put into D4. I put the two LEDs in D5 and D6. Then, I put the button module into D7.
Step 4: Coding for the Arduino
I learned a few lines of code for commands like turning on and off the LEDs and triggering the motor or sound module. I then wrote this code into the Arduino program on my computer and downloaded it onto the Arduino. We went through a lot of trial and error to figure out details like which speeds would work best and how long to let each command last.
Our final decision was to have all three operations (the LEDs, motor, and sound) triggered by the button module. We coded so that the LEDs would turn on when the button is pressed and stay on until the button is let go. Similarly, we coded so that the motor would turn from the "-300" position to the "100" position when the button is pressed, and it would stay at that position into the button is let go. The sound would also be triggered by the button, but it would continue for 20 seconds, even if the button is let go.
Here was the code I used:
int button1 = 4;
int press1 = 0;
int led1 = 5;
int led = 6;
int pinPlay = 2;
press1 = digitalRead(button1);
if (press1 == 1)
digitalWrite(pinPlay, HIGH); //Stop Sound
Step 5: Recording the Sound
I recorded the crying sound effect from a youtube video (above). Then I uploaded that recording onto the sound module using the Arduino.
Step 6: Reconfiguring the Doll
Now that the technological aspects of the doll were mostly done, I began to work on the doll itself. I started by cutting a large slit in the neck and removing most of the stuffing from the head, so I would be able to easily insert the modules from the Arduino through the neck. I also removed a little bit of stuffing from the body, so it would bend easier, therefore allowing it to sit, rather than just standing straight. Then I drilled a large hole in each eye, where the LEDs would poke out. Finally, I made a small incision in the doll's left hand, where I would place the button module.
Step 7: Mounting the Doll
My next step was to build a small wooden mount, so I could attach the doll to a stable platform. I used hot glue to ensure a secure attachment. I also wrapped rubber bands around the wood and the doll, to keep it all in place until the hot glue was set and dry. I ended up leaving the rubber bands on the doll because then helped the doll stay on the mount and not shift around. Once the glue dried, I screwed in two nails at the the very bottom of the mount, which went through the back of the vertical piece and into the base of the piece that the doll was on top of.
Step 8: Attaching the Sound Module
Behind the doll, I glued down the speaker, which would play the recording of the baby crying. I made sure it was well hidden. That way, it would seem more realistic like the doll was actually crying, whereas leaving the speaker visible would allow people to know that's where the sound was actually coming from.
Step 9: Inserting the LEDs
I inserted the LEDs through the hole in the neck. I put them into the head (that was already unstuffed) and then pushed them through the holes that I drilled in the eyes. Since the LEDs were not very secure in their modules, I used electrical tape to hold them together while they were inside the doll.
Step 10: Attaching the Motor
Then, I attached the motor behind the top of the wooden mount, using hot glue. I used the hot glue again to attach one end of the motor to the back of the doll's head, which was meant to turn the head when the button is pressed. Since the motor attachment was very short, I hot glued a thin wooden rod to the end that would go on the doll's head.
Step 11: Applying the Button Module
In order for all of the other modules to work, I needed the button module to trigger them. I put this module in the doll's left hand, so that all of the operations would be triggered when the hand is held.
Step 12: Mending the Wounds
Once I attached all of the modules, I stuffed the doll again with all of the stuffing I had removed. Then I glued the head back together and pinned the doll's hand closed. Keep in mind that this part doesn't have to look perfect. The doll is meant to look a little messy and scary. So I wasn't afraid to leave a little glue oozing out or leave some rubber bands visible.
Step 13: Writing the Sign
Of course, I needed to give passersby some simple directions so they would know how to operate the prop. However, I still wanted this piece to fit the theme, and I still wanted it to look creepy. I achieved this by writing "Hold my hand" on a thick white piece of paper, attempting to make the writing look messy and childish, as if a baby had written it. I also drew an arrow pointing to the hand with the button module inside. I attached the sign to the doll with hot glue, so it would stay in place. The wet-looking effect of the sign was actually accidental (caused by rain), but I ended up liking the way the splattered marks made the sign look even scarier.
Step 14: Ready for Action
Finally, the doll is ready to be used! I connected the Arduino to an outlet, by inserting the chord into the barrel jack. Once the hand is squeezed, the doll is now capable of moving its head, flashing its eyes, and crying!