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dcb · 10-04-2010, 09:31 AM

the PSTR function is a way to define a string (or other data), such that it isn't automatically loaded into ram but only in flash.

Code:

the following takes up an extra 16 bytes of ram, always:
 LCD::print("OpenGauge       ");

whereas this tells the compiler to not pre-allocate ram for the string, it will be fetched by getStr only when needed:
  LCD::print(getStr(PSTR("OpenGauge       ")));

You should make a visit to avrfreaks.net sometime, there is a plethora of tricks and gotchas with microcontrollers.

10-04-2010, 09:31 AM	#4 (permalink)
dcb needs more cowbell Join Date: Feb 2008 Location: ÿ Posts: 5,038 pimp mobile - '81 suzuki gs 250 t 90 day: 96.29 mpg (US) schnitzel - '01 Volkswagen Golf TDI 90 day: 53.56 mpg (US) Thanks: 158 Thanked 269 Times in 212 Posts	the PSTR function is a way to define a string (or other data), such that it isn't automatically loaded into ram but only in flash. Code: the following takes up an extra 16 bytes of ram, always: LCD::print("OpenGauge "); whereas this tells the compiler to not pre-allocate ram for the string, it will be fetched by getStr only when needed: LCD::print(getStr(PSTR("OpenGauge "))); You should make a visit to avrfreaks.net sometime, there is a plethora of tricks and gotchas with microcontrollers. __________________ WINDMILLS DO NOT WORK THAT WAY!!!