Reading responses from Serial not working

Projects Programming
2 
String incomingByte="";   // for incoming Serial data

That is a horrendously stupid name. A byte is NOT a String.

                len = incomingByte.length();
                char reso[len]={};
                incomingByte.toCharArray(reso, 50);

The second argument to the toCharArray() method is the size of the array to write to, not some number you pulled out of your ass.