I have some friends who own a cupcake shop--so, for no particular reason, I decided to make a talking cupcake.
I scanned a cupcake, then split it into a top and bottom half. I hollowed out the bottom half and adjusted the parts to accommodate motors and electronics.
This has a 20 second limit on the recordable message (change the message any time you like) and it plays whenever someone walks by. You could make a sandwich or other talking advertisement item of your choice.
Parts include an Arduino Uno, a voice recording module--Radio Shack or Amazon
a servo motor, a 9 volt power supply, a usb power supply, Parallax PIR sensor and 3d printed cupcake.
The 3d files are on Thingiverse.
Print the bottom combo, top combo and servo holder.
Add screws to the servo horn and secure the servo horn to the motor
Place the servo motor in the servo bracket.
Paint the cupcake. Add eyelashes and google eyes.
Glue the PIR sensor into the cupcake bottom. Glue the speaker base into the bottom and drop the speaker in place. Secure the speaker by gluing the 3d printed speaker holder above the speaker wires.
Solder wires to the wire extensions that go to the control box (3d printed).
Remove the pushbutton "play" switch and solder wire wrap wires to the traces. This is the most challenging part of the project.
Wire according to the schematic.
Input the software into the Arduino.
Press the "record" button on the sound module. Wait about one second, then start your message. Get close to the microphone and speak loudly and distinctly. Release the "record" button when the message is complete.
Add padding between the lips of the cupcake. Add rubber feet to the bottom of the cupcake to prevent "dancing" around.