Introduction to the use of Arduino progmem static storage area

Arduino PROGMEM Introduction to the use of static storage area

keyword PROGMEM

because Program store and SRAM Memory is separate , So there is something like 328P Yes 32K Of FLASH Program store and 2K Of SRAM Dynamic memory , Of course, ROM,PROGMEM Store data in flash memory ( Program ) Memory, not dynamic memory SRAM in .

• promem A keyword is a variable modifier , It should only be used for pgmspace.h Data types defined in . It tells the compiler “ Put this information into flash memory ”, Not the usual SRAM in .
• PROGMEM yes pgmspace.h Part of the library . It is automatically included in IDE In the new version of . If you use it IDE Version below 1.0(2011), At the top of the program code, you need to add the header file library that contains the introduction , like this :#include <avr/pgmspace.h>
• although promem Can be used for a single variable , But it's only worth it if you need to store larger blocks of data , This is usually the simplest array ( Or others c++ data structure ).
• Use promem It is also a two-step process . After storing the data in flash memory , It requires special methods ( function ), It's also defined in pgmspace.h In the library , Read data from program memory to SRAM in ,