CASE statement and OR

I want to use a SWITCH..CASE statement to check for certain characters. I want to work with either upper or lower case. So I have

  switch(inByte) {       //What letter is it?
    case 'S':
    case 's':
      ltrS();            //handle 'S' as 1st letter
      break;
    case 'V':
    case 'v':
      ltrV();            //handle 'V' as 1st letter
      break;
    case 13:          //carriage return?
      digitalWrite(9,HIGH);
      break;
    }

Is there a way to put both the upper and lower case on 1 line? eg, case 'S' or 's':

You could use the toupper function to convert letters to upper case:

#include <ctype.h>


    inByte = toupper(inByte);  // convert lower case to upper case
    switch(inByte) {       //What letter is it?
    case 'S':
      sltrS();            //handle 'S'  or 's' 
      break;
    case 'V':
      ltrV();            //handle 'V' or 'v' 
      break;
    case 13:          //carriage return?
      digitalWrite(9,HIGH);
      break;
    }

this actually results in bigger code than the version you posted but would save you typing if you had lots of letters to switch on.

note that toupper needs the #include <ctype.h>

Thanks. I had considered converting everything to uppercase when I get the character from the COM port. Didn't know what the function was though. (I was just going to subtract 32, or whatever the number is, if between 'a' and 'z').

I was just going to subtract 32, or whatever the number is, if between 'a' and 'z'

You would have been better off subtracting the difference between 'a' and 'A'. That's what the toupper function does, for all values between 'a' and 'z'.