I’m new to building circuit boards and am contemplating designing a simple board (not necessarily for FRC use) with gyros, accelerometer and some other stuff. But now I’m trying to figure out what kind of microprocessor to go with. I probably won’t go with Motorola because they’re not as friendly as Microchip or Atmel. I know this can be a hotly debated subject (PIC vs AVR with AVR Fanboys usually being the loudest), but would like to hear both sides of the argument from other engineers.
I prefer arduino, but only because this is the platform that I’m relearning embedded programming on this summer.
I college I learned on a PIC18F452 and was the only person in a 18-person class to finish all 40 projects. My last project was an alarm clock that could be set to any time zone. I used to know all of its features like the back of my hand… but alas I moved on to other things… The PIC was a great processor that was powerful for what it was and was very reliable for simple tasks.
As I get better at things I may move on to Raspberry Pi in order to have a fully integrated system on my quadrotor that includes plenty of resources for autonomous routines, pilot-in-the-loop commands (a requirement of the FAA for hobby UAVs btw), data/image logging, etc. Using a Pi would require decent knowledge of Linux and Linux drivers to integrate custom circuitry, so I’ll see how it turns out in the next year or so.
I’ll be the oddball and throw in a vote for Picaxe M2 chips. Perhaps not for what you want to do, but I think they have some nice features generally speaking.
I wouldn’t really consider arduino a microcontroller. It’s software installed on an atmel chip. I have an arduino uno, but there are more advanced things I want to do with it.
ARM Cortex M3 is my preference for most micorcontroller projects. Multiple companies make this architecture and if you want to upgrade your chip, your code is fairly portable.
To find the chip with the peripherals you need, I usually do a parameter search on digikey or mouser looking for evaluation boards with the ARM Cortex M3 architecture.
Octopart also has a nice interface for searching evaluation boards.
Actually, I just had another idea (this time for FRC)…something that we’ve never really done. We haven’t really done much data acquisition to ensure our devices are running properly. I’d like to design a board to collect voltages and communicate with the cRIO via SPI. This sounds kind of stupid because cRIO is a platform to accept DAQ cards, but just one cRIO DAQ board from NI can eat up your whole budget for your robot. There’s got to be a much less expensive way to do this.
It would be nice to run wires from the output of victors or jags to measure the amount of voltage actually being applied. Not only would this be useful for diagnostic purposes (is there something wrong with my victor? My motor? etc.), it could help keep your robot from destroying itself (like if a motor should be running, but it isn’t). They wouldn’t have to necessarily be that high of bit resolution (16-bit should be fine) nor extremely fast. Anyway, just a thought.
I’ve had experience with Freescale and Microchip.
Of the two, I prefer Microchip. I can readily get samples of their products (something like 2 samples per month for life), if I need more than that I can buy single chips for cheap ($1-$4 for PIC18), the IDE is now Netbeans based instead of a proprietary platform (used to be mplab, versus Freescale which is still codewarrior based).
Last thing is that I can get a Pickit3 for about $100, or a knockoff Pickit2 with a ZIF socket for about $40, which is a nice price point for a hobbyist.
You can get a Pickit 3 for a lot cheaper than that!
I bought the Pickit 3 Debug Express for $70 this morning.
http://www.microchipdirect.com/ProductSearch.aspx?Keywords=DV164131
You can get just the Pickit 3 hardware for even cheaper
http://www.microchipdirect.com/productsearch.aspx?Keywords=PG164130
Price must’ve dropped since I last checked.
Either way its good for the hobbyist. 
I have to agree with Andy; The M3-Cortex is a beautiful architecture. Great combination of ecosystem, power, and get’r’dun.
Note: I used to work for TI in their M3-Cortex division.