Hey thanks for the replies. I cut down the code as the whole thing is 350+ lines. But i have no edited the code to add the missing values/functions.
"char receivedChars" is a character array that is populated inside void recvWithStartEndMarkers()
void recvWithStartEndMarkers() is a copy almost word for word of example 3 here It is a non blocking hardware serial reader which i've changed to use softwareserial.h
You may well be correct. I didn't research the function correctly as its about 35 degrees by my pc at the moment.
The recvWithStartEndMarkers() concatinates a null onto the array.
receivedChars[ndx] = '\0'; // terminate the string
Whether that null is the same as a C-style Null i have no clue.