An alert system

Hi everyone. I'm quite new. I'm working on a project that involves the following: 1) Arduino Uno, 2) Triple-axis BMA180 Acceleromter ( [Datasheet/specs:] {Example code: (Thanks to m.ryandesign)}, 3) Devantech SRF02 Ultrasonic Range Finder ( {Example code:}, 4) A simple piezo-speaker {Example code:}.

My main goal here is to install it on some moving vehicle, e.i., robots, carts, automobiles, etc. When the car's in motion the whole alert system should be on stand-by. When the car's stopped, the system should detect whether something's in front, and when it is clear in front, it should give a warning thru the speaker in a certain time interval. This is where the ultrasonic range finder comes in. However, when the care moves before the time interval, the system should go to the standby mode. This is where the acceleromter comes in. This is pretty much the whole of it. I got around messing with each component, and they seem to be working properly with the codes found online. I also got to work with I2C interface, which is pretty new to me. Any pointers on how I should go about doing this will be much appreciated. At this point, I'm hesitant about how to integrate every component so the system can work as a whole. I will provide more information if anyone's interested. Thanks.

You have the high-level blocks worked out. Now you start combing them.