[pblankenbaker]

It looks like your command enables a PID controller to perform the turn. This is OK (we do this as well). However, I don't see where you turn the PID controller off (disable it) in your command's end() and interrupted() methods.

I suspect this is why you are unable to drive after running your command (the command's PID continues to run in the background and "fights" with your normal drive command at setting the motor power).

Adding pid.disable() to the end() method and having interrupt() invoke end() should clean up this issue.