johnwasser:
Close. Remember that if the format string is in PROGMEM you have to use sprintf_P(). Other than that it looks correct to me (depending on the declarations of buffer, P_enabled[], v, etc).
I know that I'm "supposed" to use sprintf_P() - but the strange thing is that it works WITHOUT it (i.e. using plain old sprintf()).
That's why I asked if I was doing it correctly. I assumed that it should fail if I use plain sprintf().
-- Roger