as an exercise I've written a sketch to take ascii data in on the serial port on an Arduino Uno and convert it to Morse code. I'm finding that if I comment out some of the code in a routine producing help text it works, if not commented out, it does not. The code is here:
(too long to sensibly post in the forum).
The block of code I've commended out runs from lines 256 - 278.
I'm wondering if the micro-controller is running out of memory? I've produced the sketch with no particular regard for memory useage. However, the code resides in program memory, not SRAM, so I'm not certain it is a SRAM issue.