correct total RAM size, FreeRam.ino malloc failure

examples/FreeRam/FreeRam.ino

@@ -3,6 +3,7 @@
 void setup() 
 {
     Serial.begin(115200);
+    Serial.println(F( "Running " __FILE__ ", Built " __DATE__));
     Serial.println(F("Starting state of the memory:"));
     Serial.println();
 
@@ -17,9 +18,14 @@ void setup()
     Serial.println();
 
     FREERAM_PRINT;
+
+    //byte *p = new byte[3000];
+    byte *p = new byte[300];  // Uno (ATmega328) only has 2k RAM
 
-    byte *p = new byte[3000];    
-
+    if(!p) {
+        Serial.println(F("could not allocate bytes for p[] array!"));
+    }
+
     Serial.println();
     Serial.println();
 
@@ -37,6 +43,9 @@ void setup()
     Serial.println();
 
     FREERAM_PRINT;
+
+    delete p;
+    p = 0;
 }
 
 void loop() 

examples/GetMemorySize/GetMemorySize.ino

@@ -0,0 +1,53 @@
+#include <MemoryUsage.h>
+
+// Simple example to report memory sizes
+
+void reportAllocation(int numBytes) {
+
+    Serial.print(F("Allocating for "));
+    Serial.print( numBytes );
+    Serial.print(F(" bytes; "));
+
+    byte *p = new byte[numBytes];
+
+    if (p) {
+        Serial.println(F("...success."));
+    } else {
+        Serial.println(F("...allocation FAILED"));
+    }
+
+    MEMORY_PRINT_HEAPSIZE
+    FREERAM_PRINT
+
+    Serial.println(F("\ndeleting byte array with delete"));
+    delete p;   // don't want a memory leak!
+    p = 0;      // don't want a dangling/obsolete pointer
+
+    MEMORY_PRINT_HEAPSIZE
+    FREERAM_PRINT
+}
+
+void setup() {
+    Serial.begin(115200);
+    delay(1000);
+    Serial.println(F( "Running " __FILE__ ", Built " __DATE__));
+
+    Serial.println(F("\nStarting conditions"));
+    MEMORY_PRINT_TOTALSIZE
+    MEMORY_PRINT_HEAPSIZE
+    FREERAM_PRINT
+
+    Serial.println(F("\nallocate a byte array with new; too big to fit in RAM?"));
+    reportAllocation(3000);
+
+    Serial.println(F("\nallocate smaller byte array with new (it should fit)"));
+    reportAllocation(300);
+
+    Serial.println(F("\nFinal conditions"));
+    MEMORY_PRINT_HEAPSIZE
+    FREERAM_PRINT
+}
+
+void loop() {
+    // User reads output from setup().
+}

src/MemoryUsage.h

@@ -136,7 +136,7 @@ extern uint8_t *__bss_end;
 /// Print free ram size on serial console.
 #define MEMORY_PRINT_FREERAM	{ Serial.print(F("Free ram:")); Serial.println((int) SP - (int) (__brkval == 0 ? (int)&__heap_start : (int)__brkval)); }
 /// Print total SRAM size on serial console.
-#define MEMORY_PRINT_TOTALSIZE	{ Serial.print(F("SRAM size:")); Serial.println((int) RAMEND - (int) &__data_start); }
+#define MEMORY_PRINT_TOTALSIZE	{ Serial.print(F("SRAM size:")); Serial.println(((int) RAMEND + 1 - (int) &__data_start)); }
 
 /// Displays the 'map' of the current state of the Arduino's SRAM memory on the Serial console.
 void SRamDisplay(void);