Dynamic memory calculation issue

Using Arduino Programming Questions
1

I run below code for Arduino Uno and it compiled successfully. But I am expecting an error since I have used uint32_t data type for the variables. It should exceed the dynamic memory, right? Because I have used 1000 uint32_t. But it just consumes 13 bytes. Why?

uint32_t x;
uint32_t data[1000];

void setup() {
}

void loop() {
data[x++]=x; 
}

Arduino console log Sketch uses 482 bytes (1%) of program storage space. Maximum is 32256 bytes. Global variables use 13 bytes (0%) of dynamic memory, leaving 2035 bytes for local variables. Maximum is 2048 bytes.

2

Welcome,

The array is not used anywhere, so it's deleted in the compiled program

3

Because you don't use the array, so the compiler optimised it away.

How is this a tutorial?

4

If the compiler not optimize remove it, it will cause the error you expect.

volatile uint32_t data[1000];

Sketch uses 514 bytes (1%) of program storage space. Maximum is 32256 bytes.
data section exceeds available space in board
Global variables use 4013 bytes (195%) of dynamic memory, leaving -1965 bytes for local variables. Maximum is 2048 bytes.
Not enough memory; see http://www.arduino.cc/en/Guide/Troubleshooting#size for tips on reducing your footprint.
Error compiling for board Arduino Uno.
5

Your post was MOVED to its current location as it is more suitable.

1 Like
6

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