Hey guys, I'm new to Arduino but I'm really excited to jump in and learn. I've done some basic electronic work before and a very small amount of programming, but I am hoping to learn more before I start college next year. Anyway, I had an idea for what my first project would be, but I'm having troubles figuring out how exactly I would do it. I was hoping some of you seasoned veterans could point me in the right direction.
So basically what I'm hoping to make is this: One central device that I would put in my room or something connected to an LED and maybe a speaker. A second, portable device that would be fairly small and possibly be able to attach to someone's car. What I'm hoping to do is make it so that when the two devices got close enough together (I'm hoping for as long a range as possible, but a few hundred feet would work fine), the central device would start to light up and make noise.
Now, my current idea is to use two XBees attached to Arduino's. The central Arduino would be searching for the signal of the second, and as they got closer together, the signal would get stronger, and the device would get louder. Now, I'm fairly certain that I could pull something like that off (please tell me if I am wrong and why, as I am hoping to learn). However, as I said earlier, I am headed for college next year, and well, money doesn't grow on trees. Buying two Arduino's and two XBees would be a decent chunk of change, especially if I wasn't certain that it would work. So I am looking for some input on my ideas. Is there any way that I could do this that would be a little bit cheaper?