Dalek Voice Changer (Arduino Shield)
Do you want to sound like a Dalek or a Cyberman for Halloween? Do you want to buy the perfect Doctor Who Christmas Gift for the geek in your life? If so, this is the Arduino project for you! This is a voice changer shield compatible with the Arduino Uno that can be used for a variety of voice changer effects from pitch shifting to ring modulation. It consists of a 12-bit ADC and a 12-bit DAC plus a low pass filter. By using the external ADC and DAC, the Arduino is left with much more processing power for manipulating the audio signal and allowing for effects to be adjusted in real-time without having to restart the sketch.
All 8 analog channels are broken out. This means you can sample multiple audio sources and/or multiple potentiometers or other analog inputs for manipulating sounds. The board doesn't contain a pre-amp for audio signals so you will need a mic with a pre-amp built in. I recommend using an electret mic breakout from SparkFun (product link) or Adafruit (product link). These are the mics that I am using in all of my video demos.
You will also need a speaker with built-in amplifier. There are many "portable MP3 speakers" available. You will need one with line-in input (bluetooth won't work).
There is an on-board LED that can be manipulated along with the sound. There are also pads for connecting a screw terminal to connect to external LEDs. This could be used to drive Dalek dome lights or the mouth in a Cyberman helmet, just as examples.