Hey Matt,
If you know some wealthy and generous people, go for it! Also, some more successful local stores might be able to support you with your projects.
Microcontrollers sure are handy when you know how to use them, I am just getting into programming for a project I am working on. There are tons of families of microcontrollers that you can use, you just have to choose one that is appropriate for your application. These specs. include processing speed (MIPS), processing power(8-bit, 32-bit?), memory (ram, sram, flash) size, I/Os, interrupts, on chip peripherals (timers, SPI, I2C).
Then you need to figure out how to program them. The best bet is to find a new controller that you can solder or get a development board (
www.olimex.com has some controllers with their crystals and I/Os easily accessed) with in-system programming capability. These are the cheapest programmers you can get a hold of, and they can still program powerful devices.
Also, you need to learn a language of choice for the controller. You can either choose to learn a low-level language or a higher level language. The lower-level language is the most tedious to work with, it is basically doing assembly instruction at a time that you specify. For more information on this, check out a controller from the various manufacturers such as
www.microchip.com www.atmel.com www.ti.com www.national.com and the list goes on, and read the datasheet on the programming language. It gives you the proper syntax and how to use each instruction.
A higher level language involves using a compiler for a different language such as BASIC and C. This is pretty much the easiest way to make a complex program, but it will run less efficient for code space then assembly language. I am using a
www.mcelect.com (i think that is right) BASCOM AVR BASIC compiler, which is extremely easy to use.
If you could consider using straight logic to control the line follower, then do it. You cannot beat the speed of logic on a controller, but it isn't as robust and you might need to make a change.
For motors, don't go to Radioshack, their stuff is garbage. Search for surplus electronics motors at
www.google.com and you'll see some places which will have some nice motors for cheap. You don't need a massive motor to do what you want.
Goodluck,
Steve