Stack size allocation in FreeRTOS - Mini Project: Build & Apply

Stack Size Allocation in FreeRTOS

📖 Scenario: You are working on a small embedded system using FreeRTOS. You need to create tasks with proper stack sizes to ensure they run correctly without wasting memory.

🎯 Goal: Learn how to allocate stack sizes for FreeRTOS tasks by creating tasks with specific stack sizes and then printing their stack size configuration.

📋 What You'll Learn

Create a FreeRTOS task with a specific stack size

Define a stack size constant

Use the stack size constant when creating the task

Print the stack size used for the task

💡 Why This Matters

🌍 Real World

Embedded systems often have limited memory. Allocating the right stack size for tasks prevents crashes and saves memory.

💼 Career

Understanding stack size allocation is essential for embedded software developers working with real-time operating systems like FreeRTOS.

1

Define a stack size constant

Create a constant called STACK_SIZE and set it to 256 to represent the stack size in words.

FreeRTOS

# Define the stack size constant
# Your code here

Need a hint?

Use #define STACK_SIZE 256 to create the constant.

2

Create a FreeRTOS task with the stack size

Create a task called vTaskFunction with the stack size STACK_SIZE using xTaskCreate. Use NULL for parameters you don't need, and priority 1.

FreeRTOS

#define STACK_SIZE 256

// Create the task with stack size STACK_SIZE
// Your code here

Need a hint?

Use xTaskCreate(vTaskFunction, "Task1", STACK_SIZE, NULL, 1, NULL); inside main.

3

Add a variable to hold the stack size

Create a variable called taskStackSize and set it to STACK_SIZE to store the stack size value.

FreeRTOS

#define STACK_SIZE 256

void vTaskFunction(void *pvParameters) {
    for (;;) {}
}

int main(void) {
    xTaskCreate(vTaskFunction, "Task1", STACK_SIZE, NULL, 1, NULL);
    int taskStackSize = 0;  // Your code here
    vTaskStartScheduler();
    return 0;
}

Need a hint?

Declare int taskStackSize = STACK_SIZE; inside main.

4

Print the stack size used for the task

Use printf to display the text "Task stack size: " followed by the value of taskStackSize.

FreeRTOS

#define STACK_SIZE 256

void vTaskFunction(void *pvParameters) {
    for (;;) {}
}

int main(void) {
    xTaskCreate(vTaskFunction, "Task1", STACK_SIZE, NULL, 1, NULL);
    int taskStackSize = STACK_SIZE;
    // Print the stack size
    // Your code here
    vTaskStartScheduler();
    return 0;
}

Need a hint?

Use printf("Task stack size: %d\n", taskStackSize); to print the value.