Plants Vs. Zombies Interactive Plush Toys!

Brains!!

Om nom nom...

Have you ever wanted to have a real-life version of the zombie from the video game?  Well, now you can!
This zombie reacts to the other objects- the Brain, the Wall-Nut and the Pea Shooter.  

The BRAAIIINNNSS  of the zombie is the Arduino. It runs off of a 9 volt battery. 

This is a project that was created in CSCI 7000: Things That Think at the University of Colorado Boulder.

Step 1: Creating the Zombie

The zombie is made from 'moss green' polyester felt, and is sewn using a simple pattern for a rag doll found online (www.sewing.circleofcrafters.com) This blog gave us good instructions on how to sew the doll together..  We downloaded the pattern in JPG format and using Adobe Illustrator (Corel Draw and Inkscape would also work), we live traced the shapes to create vector files.  We then sized the pattern to the zombie, and cut out the shapes using a laser cutter.  

Then, fold the arm and leg shapes in half and sew up the rest. turn them inside out and stuff them with polyfil or other stuffing. Next, take one of the body shapes and sew a zipper into it and cut the felt above the zipper to allow it to move. With the zipper slightly open, place the body cut out with the outside of the zipper facing up, and pin the arms and legs to the felt so that they point in the direction opposite to that of which you want them to go (legs pointing up and the arms pointing in) and place the other piece of body felt on top and pin it in place. Now you can sew around the edge, making sure that you sew into the arms and legs.  When you have gone around the whole body, you then open the zipper,  and turn it right side out.

The shirt is a simple piece of white cloth with holes cut out for arms, and hot glued in the back. The collar is made by cutting a small slit and folding the top over.

The tie is just a piece of red felt that is hot glued in place.

The jacket is made by folding the fabric so that the fold is up (away from you). The fold will be where the shoulders go. Then sew up the sides to make a 'T' shape. Turn right side out and rip (or cut) the right sleeve off so that it looks jagged and torn.

The pants are made by sewing two pieces of denim up the sides and up the crotch and turned inside out. The left pant leg is ripped so that the knee is showing.

Cut the mouth, nose and teeth from felt and glue them on to the face. 

Step 2: BRAAIIINNNSSSS!!!!!

Upon 'seeing' the brains, the zombie goes wild. Braiiinnnnssss!! He exclaims.

To make the brains, we started with a styrofoam egg and shaped it by flattening the base and creating a seam in the middle to separate the left and right hemisphere. We glued the RFID button to the styrofoam and then covered the styrofoam with textured grey felt and attached it using hot glue. 

Step 3: Pea Shooter

The pea shooter was created using polyester felt. We created the pattern on Inkscape, and then cut the shapes out using the laser cutter. the head is made up of four identical pieces and sewn together by hand.  The RFID button is inserted in the 'mouth' of the pea shooter. The leaf was cut out by hand, and then the veins of the leaf were sewn in. The stem and the leaves were made in the same fashon, except that the stem has a wire sewn down the center of it to keep the head up.

The pot is filled with 'Great Stuff' foam and covered with a nice piece of brown felt.  Then the wire from the stem is shoved down into it  and secured with hot glue.

Step 4: Wall-nut

In the game, the Wall-nut stands his ground in front of the zombies, defending the house by allowing the zombies to munch on him. 

We created the Wall-nut using the same method as the brains: Styrofoam core with felt hot glued to the outside.  There is a RFID button sandwiched in between the styrofoam and the felt.

His eyes are modified googly-eyes; we took out the black pupils, cut them down and then reinserted them.

Step 5: MP3 Player Hack

To make the zombie talk, we used a cheap chinese ipod shuffle knock off and hacked it using the same method as outlined in this instructable, however, the pin outs are a little different on our mp3 player as that of the player in the Instructable.

We removed the board from the case and hard wired the audio outputs directly to our amplifier board (as seen in the next step). We also hard wired the switches that control the volume, play/pause, next track, and previous track. We disconnected the battery, and connected the the power inputs to the Arduino outputs.

The MP3 player board then attaches directly to the sound amplifier board that we created.

We used the Audio Hijack Pro software to record sounds directly from the PVZ game.  Audacity was used to shorten the tracks, and were then loaded onto the microSD card.

Step 6: Amplifier

In order to hear what is being played on the MP3 player, we need to amplify the signal and run it to a speaker. We used a simple amplifier circuit that uses an LM386 audio amplifier (this datasheet has a good schematic), capacators and resistors. We attached the MP3 player directly to the protoboard so that we didn't have to run wires between the two.  It also uses it's own 9 volt battery to power the amplifier.

Step 7: RFID Reader

The RFID tags that are hidden in the pea shooter, brains, and wall-nut are read by the arduino using the Innovations ID-20 RFID reader from SparkFun Electronics.  SparkFun also sells a great break out board that makes hooking up to it easy. We used the bildr tutorial  for help on the wiring and code writing.

Step 8: Speaker

The speaker is a 2.5 inch diameter 8 ohm speaker found in the junk pile of our lab. We soldered two leads to it and then made a speaker grille for it so that it wouldn't get ruined being inside the plush toy. The grille is made from stainless steel mesh and is formed into a dome shape using a ball. it was cut to shape and then attached to the speaker using three screws. The sharp edges were covered up using hot glue.

Step 9: Soft Switch

To conserve battery power, we wanted the pulse sensor to only turn on when we wanted our pulse taken. In order to do this, we designed and installed a soft switch (say that three times fast) to turn on and off the pulse sensor.

The soft switch is made with a foam 'doughnut' with conductive fabric on each side. When the doughnut is squeezed, the conductive fabric on each side can touch, closing the circuit. When let go, the foam separates the conductive fabric, opening the circuit. (We got the idea form this instructable.)

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Step 10: Pulse Sensor

We planned on using a pulse sensor from MAKE so that the zombie can read your pulse and display it in his LED eyes, however, upon testing, we found that the pulse sensor is designed to run at 115200 baud and the RFID reader only works at 9600 baud.  This presented a problem that we weren't capable of solving in the time allotted for this project.

For the future, we would like to run the pulse sensor off of a Lilypad Arduino separately from the rest of the electronics.

Step 11: Tri-Color LED Eyes

The zombie's eyes are made using large (about 1/2" diameter) googly eyes, and modified using the "googly eye mod," which involves removing the black pupil, trimming it down, and replacing it in the eye, sealing it with hot glue. 

Behind the googly eyes are two RGB LEDs (one for each eye) The red and blue channels are wired in parallel, so that only one Arduino pin is required for each color.  The green channel for each LED is controlled independently, so that we can make the eyes different colors (for example, we can turn on the red channel and one green channel to get one yellow eye and one green eye. 

Step 12: Assembly

Now, put it all together.  We stacked the protoboard (with the MP3 player and amplifier) on top of the Arduino, and put the RFID reader below it.  We covered any wires with felt or craft foam to keep the leads from shorting.