FreeRTOS architecture overview - Mini Project: Build & Apply

FreeRTOS Architecture Overview

📖 Scenario: You are learning how FreeRTOS works inside an embedded system. Understanding its architecture helps you write better multitasking programs.

🎯 Goal: Build a simple FreeRTOS program that creates tasks and uses the basic architecture components like tasks, scheduler, and queues.

📋 What You'll Learn

Create task functions with exact names

Create task handles with exact names

Use FreeRTOS API functions with correct parameters

Print output to show task execution order

💡 Why This Matters

🌍 Real World

FreeRTOS is used in embedded devices like IoT gadgets, wearables, and industrial controllers to manage multiple tasks efficiently.

💼 Career

Understanding FreeRTOS architecture is essential for embedded software engineers working on real-time systems and multitasking applications.

1

Create two FreeRTOS tasks

Create two task functions called Task1 and Task2 that each take a void *pvParameters argument. Also, declare two task handles called Task1Handle and Task2Handle initialized to NULL.

FreeRTOS

// Define Task1 and Task2 functions
// Declare Task1Handle and Task2Handle as TaskHandle_t initialized to NULL
// Your code here

Need a hint?

Define two functions with the exact names and parameters. Declare two task handles as TaskHandle_t variables set to NULL.

2

Create tasks in main and start scheduler

In the main function, create the two tasks using xTaskCreate with the exact names Task1 and Task2, stack size 100, priority 1, and store their handles in Task1Handle and Task2Handle. Then start the scheduler with vTaskStartScheduler().

FreeRTOS

#include "FreeRTOS.h"
#include "task.h"

TaskHandle_t Task1Handle = NULL;
TaskHandle_t Task2Handle = NULL;

void Task1(void *pvParameters) {
    for(;;) {
        // Task1 code
    }
}

void Task2(void *pvParameters) {
    for(;;) {
        // Task2 code
    }
}

int main(void) {
    // Create Task1 and Task2 with xTaskCreate
    // Start the scheduler with vTaskStartScheduler
    // Your code here
}

Need a hint?

Use xTaskCreate to create each task with the exact parameters. Then call vTaskStartScheduler() to start running tasks.

3

Add task code to print messages

Inside the infinite loop of Task1 and Task2, add code to print "Task1 is running" and "Task2 is running" respectively using printf. Add a call to vTaskDelay(1000 / portTICK_PERIOD_MS) after each print to delay for 1 second.

FreeRTOS

#include "FreeRTOS.h"
#include "task.h"
#include 

TaskHandle_t Task1Handle = NULL;
TaskHandle_t Task2Handle = NULL;

void Task1(void *pvParameters) {
    for(;;) {
        // Print "Task1 is running"
        // Delay 1 second
        // Your code here
    }
}

void Task2(void *pvParameters) {
    for(;;) {
        // Print "Task2 is running"
        // Delay 1 second
        // Your code here
    }
}

int main(void) {
    xTaskCreate(Task1, "Task1", 100, NULL, 1, &Task1Handle);
    xTaskCreate(Task2, "Task2", 100, NULL, 1, &Task2Handle);
    vTaskStartScheduler();
    for(;;) {}
}

Need a hint?

Use printf to show the task running message. Use vTaskDelay to pause the task for 1 second.

4

Run and observe task output

Run the program and observe the output. It should print alternating lines "Task1 is running" and "Task2 is running" every second.

FreeRTOS

#include "FreeRTOS.h"
#include "task.h"
#include 

TaskHandle_t Task1Handle = NULL;
TaskHandle_t Task2Handle = NULL;

void Task1(void *pvParameters) {
    for(;;) {
        printf("Task1 is running\n");
        vTaskDelay(1000 / portTICK_PERIOD_MS);
    }
}

void Task2(void *pvParameters) {
    for(;;) {
        printf("Task2 is running\n");
        vTaskDelay(1000 / portTICK_PERIOD_MS);
    }
}

int main(void) {
    xTaskCreate(Task1, "Task1", 100, NULL, 1, &Task1Handle);
    xTaskCreate(Task2, "Task2", 100, NULL, 1, &Task2Handle);
    vTaskStartScheduler();
    for(;;) {}
}

// Run the program and observe the output

Need a hint?

Run the program on your FreeRTOS environment or simulator. You should see the two messages printed repeatedly every second.