Can the arm be programed in C?
This depends on which microcontroller you want to use. If you use the Atom PRO, it can be programmed in C. The same would be true of a Microchip PIC or Atmel AVR (Atmega8, Atmega16, Atmega168, Atmega128, etc). There is no facility to program the Basic Atom in C.
8-Dale
The arm is controlled by the SSC-32. The SSC-32 manual covers the command structure. Writing a program in C for the arm is just a simple matter of sending serial commands. This isn’t terribly difficult as far as programming goes, but I have no experience with it. Perhaps some experienced programmers can point you in the right direction.