Arduino 顯示SRAM記憶體容量

 

#include <Streaming.h>

int freeRam ()
{
  extern int __heap_start, *__brkval;
  int v;
  return (int) &v - (__brkval == 0 ? (int) &__heap_start : (int) __brkval);
}

void setup()
{
  Serial.begin(115200);
  Serial << "1. RAM: " << freeRam () << "\n";
  byte *ptr1= (byte*)malloc(1024*sizeof(byte));
  Serial << "2. RAM: " << freeRam () << "\n";
  byte *ptr2= (byte*)malloc(1024*sizeof(byte));
  Serial << "3. RAM: " << freeRam () << "\n";
  free(ptr2);
  Serial << "4. RAM: " << freeRam () << "\n";
  free(ptr1);
  Serial << "5. RAM: " << freeRam () << "\n";
}

void loop()
{
}

使用Mega2560測試，Mega2560內建 SRAM 8KB = 8192 Byte
下圖是程式執行結果，可以看出記憶體容量的變化情形

 

參考資料

http://playground.arduino.cc/Code/AvailableMemory
https://learn.adafruit.com/memories-of-an-arduino/measuring-free-memory
http://stackoverflow.com/questions/8649174/checking-memory-footprint-in-arduino
http://arduino.cc/en/Main/arduinoBoardMega2560