1. What motor do u want to use ? DC motor or 3-phase motor or 1-phase motor, or BLCD motor, or step motor.... ?
2. What type of PIC microcontroller do u want to use ? 8 bit, 16 bit or 32 bit ?
3. Do you know anything about PID algorithm ? Do you know how is digital PID, how to convert analog PID to digital PID, how to identify parametter of motor ? How to give parametter of PID controller (Kp, Ti, Td)...
You should give a detail question, you'll give a detail answer !
Best regard !