PaulS:
A couple corrections. What you need are ints, not strings. Ditch the String class. You will run out of memory that way.A fixed array of chars that you store c in (and increment an index and add a NULL terminator to) will, overall, use less memory. Each time you encounter a comma, call atoi() to convert the value to an int, and reset index (and put a NULL in the 0th position of the array).
While I understand what you're explaining to me, the whole process of converting from one to the other is elusive to me. The fixed array, would that be for the 5 elements I will eventually end up with, or is that for each character read to be stored in prior to converting to INT?