I am using the PB0 pin (one of the LCD pins) and setting it to high or low using a bumper. When I compile my code in AVR it gives me errors and warnings for the declarations that are giving for Digital I/O. https://www.pololu.com/docs/0J18/4
It seems that the header files do not include the #defines for the IO_B0 pin and the functions for set_digital_input() and is_digital_input_high().
anyone know why this is?
In general, you should post your code and the errors if it is not compiling. However, in this case I think I know what your problem is - the 3pi.h file is a specialized version of orangutan.h that does not include functions that are not necessary for normal 3pi use, some of which can conflict with the 3pi setup. You can just include orangutan.h after 3pi.h to get the additional definitions that you need.
In fact, you can always leave out the 3pi.h include file and use only orangutan.h if you are willing to configure your line sensors using the functions in the QTR sensors library yourself.
Thanks for pointing this out. We will probably include the digital I/O support, servo pulse generation, and a few other features in 3pi.h when we make our next release of the library.