Priority numbering in FreeRTOS - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to set a task priority to the highest level in FreeRTOS.

FreeRTOS

vTaskPrioritySet(taskHandle, [1]);

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

AconfigMAX_PRIORITIES - 1

BconfigMAX_PRIORITIES

C1

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using configMAX_PRIORITIES as the highest priority causes errors.

Setting priority to 0 is the lowest priority, not highest.

In FreeRTOS, priorities start at 0 (lowest) and go up to configMAX_PRIORITIES - 1 (highest). So the highest priority is configMAX_PRIORITIES - 1.

2fill in blank

medium

Complete the code to create a task with priority 2 in FreeRTOS.

FreeRTOS

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

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

AconfigMAX_PRIORITIES

BconfigMAX_PRIORITIES - 1

C2

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using configMAX_PRIORITIES as priority causes errors.

Setting priority to 0 creates the lowest priority task.

The priority parameter sets the task priority. Here, setting it to 2 means the task has priority level 2.

3fill in blank

hard

Fix the error in setting a task priority to the highest level.

FreeRTOS

vTaskPrioritySet(taskHandle, [1]);

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

A1

BconfigMAX_PRIORITIES

C0

DconfigMAX_PRIORITIES - 1

Attempts:

3 left

💡 Hint

Common Mistakes

Using configMAX_PRIORITIES instead of configMAX_PRIORITIES - 1.

Confusing priority numbering starting at zero.

The highest priority is configMAX_PRIORITIES - 1. Using configMAX_PRIORITIES is invalid and causes errors.

4fill in blank

hard

Fill both blanks to create a task with the lowest priority and then increase its priority by 1.

FreeRTOS

xTaskCreate(taskFunc, "Task", 500, NULL, [1], &handle);
vTaskPrioritySet(handle, handle->uxPriority [2] 1);

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A0

B+

C-

DconfigMAX_PRIORITIES - 1

Attempts:

3 left

💡 Hint

Common Mistakes

Using configMAX_PRIORITIES as initial priority causes errors.

Using '-' instead of '+' decreases priority.

The task is created with priority 0 (lowest). Then its priority is increased by 1 using the '+' operator.

5fill in blank

hard

Fill all three blanks to create a task with priority 3, then set its priority to the highest level.

FreeRTOS

xTaskCreate(func, "Tsk", 256, NULL, [1], &h);
vTaskPrioritySet(h, [2]);
configASSERT([3] <= configMAX_PRIORITIES - 1);

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

A3

BconfigMAX_PRIORITIES - 1

Ch->uxPriority

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using 0 or configMAX_PRIORITIES as priority values incorrectly.

Not using the task handle's priority for assertion.

The task is created with priority 3. Then its priority is set to the highest level configMAX_PRIORITIES - 1. The assertion checks that the priority is valid by comparing the task's current priority h->uxPriority.