My own Arduino shield is finally coming to market! I've been working on this since March of this year. It basically turns an Arduino into a cost-effective and powerful prop controller for use with the Halloween industry. Typically you would use this to control up to 4 pneumatic solenoid valves for prop animation, although you can the relays to control any load up to 125VAC 10A or 30VDC 10A. There's an on-board EEPROM chip that allows you to record 15 separate animations. Animation 0 can be set to run in a continous loop (ambient) until the prop is triggered. Triggering is done by hooking up a motion sensor, pressure mat, etc to a screw-in terminal. Trigger voltage can be configured in software. There's also a header on board for an MP3 module that takes SD cards. Each animation slot is tied to a different MP3 file.
There's 2 ways to program your animations on the MonsterShield. You can "key-bang" the animation by using the optional detachable keypad that connects using a standard cat5 ethernet cable. Or you can plug the Arduino/MonsterShield into your computer and use the Windows MonsterShield Editor visual editing software to edit, download, and upload your animations to and from the MonsterShield. The software is actually one of the features I'm really proud of. You can interact with the MonsterShield in realtime when it is connected to your computer and using our software.
Of course we didn't want to stop there. We've got the hobbyist and hackers in mind, too. You can order the MonsterShield with or without stackable headers. You'll have access to the the secret sauce (Arduino sketch) that makes the MonsterShield work. Our Arduino sketch also implements an easy-to-use serial protocol that you could utilize to turn the MonsterShield into a computer-controlled home automation controller. We'll be publishing the serial interface protocol and command list shortly. Of course you could pitch our sketch and write your own, or reuse our routines to think up your own stuff.
For more information, you can visit our website at http://www.hauntsoft.com