When I try to compile ardupilot library 2.8.1 using Arduino 1.6.2 it gives following error.(Please see attached text file). But this library compile without any error with Arduino 1.0.6. Why this happen??? :-\
Ardupilot Library CompilationError.txt (7.54 KB)
There must be a something missing that defines prog_char_t, you could replace it with char.
The other error for prog_char is there as these are now deprecated and aren't available by default.
At the top of the files containing the prog_char_t and prog_char errors (BetterStream.h, AP_Common.h) you can add a typedef to provide the type:
typedef char prog_char;
typedef char prog_char_t;
Or you can use a text search and replace them all with char.