I have a problem detecting -1.
I'm reading characters from serial port using in c written routine which returns -1 value if buffer is empty. Everthing works fine if i just receiving the ascii characters, but must receiving hex characters too, like 0xFF. I would like to know if i'm working right.

receving a char
c = com_getchar();
i = c&0xFF;
if (i!=-1) then displaychar(c);


thanks