Hello,

I defined in .h file:
sbit key0 = P1^1;
sbit key1 = P1^2;
//more keys here as needed
#define MaxKey N // number of keys used

and have a function in .c file:
unsigned char keyState(keyID)
{
switch(keyID) {
case 0:
return key0;
break;
#if MaxKey>1
case 1:
retrun key1;
break;
#endif
// for each key, enclose case statement in #if
#if MaxKey>N
case N:
return keyN;
break;
} // end switch
}

I can then add any number of keys in .h file without touching .c file. The program works but programming style is not satisfactory. Can it be more elegant?