How do you optimize memory usage in an Arduino sketch?
Optimizing memory usage in an Arduino sketch is crucial, especially on devices with limited SRAM (e.g. only 2 KB on the ATmega328P ). Here's a guide on how to do it effectively: 1. Understand Arduino Memory Types Memory Use Flash Program code & constants ( PROGMEM ) SRAM Variables, arrays, stack/heap EEPROM Non-volatile data storage (optional) 2. Reduce SRAM Usage (Key Focus Area) Use F() Macro Store string literals in Flash instead of SRAM : cpp Serial. print ( F ( "This is stored in Flash" )); Use PROGMEM for Constant Data Store arrays, strings, or lookup tables in program memory: cpp const char msg[] PROGMEM = "Hello" ; Access with: cpp char buffer[ 6 ]; strcpy_P (buffer, msg); Minimize Global Variables Global variables are allocated in SRAM. Reduce usage or convert to const + PROGMEM where possible. 3. Use Smaller Data Types Replace int (16-bit) with byte or uint8_t (8-bit) where possible. Use float only when necessar...