Why RTOS over bare-metal in FreeRTOS - See It in Action

Why RTOS over bare-metal

📖 Scenario: You are working on a small embedded device that controls home appliances. You want to understand why using a Real-Time Operating System (RTOS) like FreeRTOS can be better than writing code directly on bare-metal hardware.

🎯 Goal: Learn the basic difference between RTOS and bare-metal programming by creating a simple FreeRTOS task and comparing it with a bare-metal loop.

📋 What You'll Learn

Create a simple task function that toggles an LED

Set up a FreeRTOS scheduler to run the task

Create a bare-metal infinite loop that toggles the LED

Print output to show which method is running

💡 Why This Matters

🌍 Real World

Embedded devices like home appliances, wearables, and IoT gadgets often use RTOS to handle multiple functions smoothly.

💼 Career

Understanding RTOS vs bare-metal is key for embedded software engineers working on real-time systems.

1

Create a bare-metal infinite loop

Write a main function with an infinite while loop that toggles an LED by calling toggleLED() and prints "Bare-metal loop running" once per loop.

FreeRTOS

void main() {
    // Your code here
}

Need a hint?

Use a while(1) loop inside main to run forever. Call toggleLED() and then print the message.

2

Create a FreeRTOS task function

Define a FreeRTOS task function called vLEDTask that toggles the LED by calling toggleLED() and prints "RTOS task running" inside an infinite loop with vTaskDelay(1000) to wait 1 second.

FreeRTOS

void toggleLED() {
    // Code to toggle LED hardware
}

int main() {
    while(1) {
        toggleLED();
        printf("Bare-metal loop running\n");
    }
    return 0;
}

// Your code here to define vLEDTask

Need a hint?

Define a function with void vLEDTask(void *pvParameters). Inside, use an infinite loop to toggle the LED, print the message, and delay 1000 ticks.

3

Set up FreeRTOS scheduler and create the task

In main, create the FreeRTOS task vLEDTask using xTaskCreate and start the scheduler with vTaskStartScheduler(). Remove the bare-metal loop.

FreeRTOS

void toggleLED() {
    // Code to toggle LED hardware
}

void vLEDTask(void *pvParameters) {
    while(1) {
        toggleLED();
        printf("RTOS task running\n");
        vTaskDelay(1000);
    }
}

int main() {
    // Your code here to create task and start scheduler
    return 0;
}

Need a hint?

Use xTaskCreate with vLEDTask and then call vTaskStartScheduler() to run the RTOS tasks.

4

Print comparison output

Add print statements before the bare-metal loop and before starting the FreeRTOS scheduler to show "Starting bare-metal loop" and "Starting RTOS scheduler" respectively. Run the program and observe the output.

FreeRTOS

void toggleLED() {
    // Code to toggle LED hardware
}

void vLEDTask(void *pvParameters) {
    while(1) {
        toggleLED();
        printf("RTOS task running\n");
        vTaskDelay(1000);
    }
}

int main() {
    // Your code here to add print statements
    xTaskCreate(vLEDTask, "LED Task", 1000, NULL, 1, NULL);
    vTaskStartScheduler();
    return 0;
}

Need a hint?

Print the message before creating the task and starting the scheduler. The output should show the RTOS messages.