When you think about electronics in your Halloween or cosplay costume, you probably imagine that it does something when you do something; it’s interactive. This guide provides some tips and suggestions for adding triggers to your costumes and props. To add light to your project, check out the "Let's put LEDs in Things!" guide.

Simple momentary pushbuttons and tactile switches can be added to any part of your costume, like the trigger on your Portal gun, the back of your Star Trek communicator, or the fingers of a glove. Adafruit carries all sorts of switches in different sizes and trigger styles. Just hook one up to your Arduino or other digital I/O board and read the switch's high/low states!

If you want to detect a gesture, like dancing or waving a magic wand, you might try a simple vibration sensor, which triggers each time the spring inside shakes around.

For more complex and precise gesture sensing, consider an accelerometer module like the FLORA nine-degrees-of-freedom sensor.

Sound is another popular trigger-- you can use the Adafruit electret microphone breakout to add audio-sensitivity to your microcontroller project, or use a volume-activated inverter for EL wire projects.

Wave Shield Voice Changer

Adafruit Microphone Amplifier Breakout guide

Tiny Arduino Music Visualizer

LED Ampli-Tie

VU Meter Baseball Hat

You can make sensors from nontraditional materials, like the velostat sensors on our Firewalker Sneakers, made by taping a piece of conductive thread to each side and reading the changing resistance as your foot steps down.