Typically this is if you "declare it" in the wrong place. When you have the "#include tts" is it outside all of the void loop and setup?
The Arduino is very sensitive about where you set values, for example if you say that x = 2 in the void setup, x=2 only in the void setup. In the void loop it has no idea what x is. To eliminate this you can declare global scope so that x = 2 no matter where it is. This is most easily done in by simply putting it at the beginning of the program before the void setup.