Arduino: malloc と free の使い方

メモリーの確保と開放のサンプルです。

sketch_aug21a.ino

int count = 0;
void setup()
{
	Serial.begin(19200);
	delay(500);
	Serial.println(F("setup *** end"));
}

void loop()
{
	char *chx = (char *)malloc(256);
	char aa[17] = "0123456789abcdef";

	strcpy(chx,"Good Morning aaaa ");
	for (int it=0; it<6; it++)
		{
		strcat(chx, aa);
		}

	Serial.println(chx);
	Serial.println("strlen(chx) = " +String(strlen(chx)));

	free(chx);

	Serial.println ("Hello " + String(count));
	delay(2000);

	count++;
}

実行結果

setup *** end
Good Morning aaaa 0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef
strlen(chx) = 114
Hello 0
Good Morning aaaa 0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef
strlen(chx) = 114
Hello 1
Good Morning aaaa 0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef
strlen(chx) = 114
Hello 2
Good Morning aaaa 0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef
strlen(chx) = 114
Hello 3
Good Morning aaaa 0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef
strlen(chx) = 114
Hello 4