string management and memory limitation

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hello arduino fans

i'm bit new @ willing learn.  building module display text messages scrolling on 16 2 lcd display.  please confirm think addition of sd card required hold text strings.  or perhaps kind of physical memory chip or other board better?  string values remain after power failure.

if use string constant ("this string constant") compiled flash (*a.k.a program memory or 'progmem') , copied ram @ run time.  if using .print() or .println() can use f() macro (stream.print(f("this string constant"));) keep string in flash , print directly flash not take ram.

there ways keep lists of strings in flash.  see: http://arduino.cc/en/reference/progmem


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