I would like to get better at building embedded devices but can't decide between avr or pic. I have the pickit 3 for pics and avr usbasp and arduino. the arduino is ok, but I want to get closer to the metal. I would like some structured projects that I can build and familiarize myself with both the hardware and more importantly the c coding i would like to get better at my c. What would you guys recommend?
I can see benefits to both sides of that discussion. Learning the guts of a system can be important if you plan on working close to hardware. Developing programs to run on MCUs like AVRs and PICs puts you about as close to hardware as you're ever going to get. That said, if you're developing programs to run on devices with an operating system like a RTOS or Linux, you're developing for the OS and probably won't go near the hardware (that's the whole point of running an OS). The APIs, at least for operating systems like Linux, will be similar on a RPi, BBB, or a desktop PC. I'm sure there are some differences, but they're more similar than different. Odds are good you're not going to get into bit shifting and tweaking clocks when developing on a RPi. 
Y'know what? Learn both. It can't hurt. RPis aren't very good microcontrollers and MCUs aren't good at desktop stuff. They each have their place.
