Arduino is an open source electronics platform comprising easy-to-use hardware and software. The microcontroller can receive input from a range of sensors and can send signals to control other devices. It is an environment for bridging computers and the physical world, also called physical computing.
Purchase an Arduino board and a USB cable, and download the software and drivers. Note that you can build your own board and circuitry, but Arduino offers the ease of use of already custom-made boards, especially if this is a new area for you.
Arduino can communicate with ActionScript and AIR via TinkerProxy or Serproxy, which are local proxies between the serial port and AIR via a socket server.
Read Mike Chambers’s blog on how to get started, at http://www.mikechambers.com/ blog/2010/08/04/getting-started-with-flash-and-arduino/.
Mike also developed a speed detector project for gear cars. It uses AIR 2.5 for Android. Two photo resistors are connected to the board that monitors when their values change. Two laser pointers beam on them at all times. When the car breaks one light and then the next, the times are sent to the AIR application that determines the speed. For more information, go to http://www.mikechambers.com/blog/2010/08/11/accelerate-flash-ar duino-based-speedometer/.
Get acquainted with sensors to get ideas. You can detect a variety of things such as light, humidity, temperature, pressure, electric current, sound, and time (for more information, see http://www.arduino.cc/playground/Main/InterfacingWithHardware).
Use of this technology is not limited to mobile devices, but such devices offer freedom of movement and open up new possibilities.