Why scheduling determines real-time behavior in FreeRTOS - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a FreeRTOS task with the correct priority.

FreeRTOS

xTaskCreate(taskFunction, "Task1", 1000, NULL, [1], NULL);

Drag options to blanks, or click blank then click option'

AtskIDLE_PRIORITY

BconfigMAX_PRIORITIES

C0

DportMAX_DELAY

Attempts:

3 left

💡 Hint

Common Mistakes

Using 0 or portMAX_DELAY as priority causes unexpected scheduling.

The task priority must be set to tskIDLE_PRIORITY or higher. Here, tskIDLE_PRIORITY is the lowest priority, ensuring the task runs when no higher priority tasks are ready.

2fill in blank

medium

Complete the code to start the FreeRTOS scheduler.

FreeRTOS

int main(void) {
    // Setup code
    [1]();
    for(;;) {}
}

Drag options to blanks, or click blank then click option'

AvTaskSuspend

BxTaskCreate

CvTaskDelay

DvTaskStartScheduler

Attempts:

3 left

💡 Hint

Common Mistakes

Calling task creation functions instead of starting the scheduler.

The scheduler is started by calling vTaskStartScheduler(). This begins task switching based on priorities.

3fill in blank

hard

Fix the error in the task delay call to ensure the task yields correctly.

FreeRTOS

void taskFunction(void *pvParameters) {
    for(;;) {
        // Do work
        vTaskDelay([1]);
    }
}

Drag options to blanks, or click blank then click option'

A1000

BportMAX_DELAY

C1000 / portTICK_PERIOD_MS

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using raw milliseconds causes incorrect delay timing.

Delays in FreeRTOS must be specified in ticks. Dividing milliseconds by portTICK_PERIOD_MS converts ms to ticks.

4fill in blank

hard

Fill both blanks to create a dictionary comprehension that maps task names to their priorities for tasks with priority greater than 1.

FreeRTOS

task_priorities = {task.name: task.priority for task in tasks if task.priority [1] [2]

Drag options to blanks, or click blank then click option'

A>

B1

C<

D==

Attempts:

3 left

💡 Hint

Common Mistakes

Using < or == will select wrong tasks.

The comprehension filters tasks with priority greater than 1 using > and 1.

5fill in blank

hard

Fill all three blanks to create a dictionary comprehension that maps uppercase task names to their stack sizes for tasks with stack size greater than 512.

FreeRTOS

task_info = { [1]: [2] for task in tasks if task.stack_size [3] 512 }

Drag options to blanks, or click blank then click option'

Atask.name.upper()

Btask.stack_size

C>

Dtask.name

Attempts:

3 left

💡 Hint

Common Mistakes

Using lowercase names or wrong comparison operator.

The comprehension maps uppercase task names to stack sizes for tasks with stack size greater than 512.