Task function signature in FreeRTOS - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a FreeRTOS task function with the correct return type.

FreeRTOS

[1] vTaskCode(void *pvParameters) {
    // Task code here
}

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

AvTaskCode

BTaskFunction_t

CTaskHandle_t

Dvoid

Attempts:

3 left

💡 Hint

Common Mistakes

Using a non-void return type for the task function.

The correct return type for a FreeRTOS task function is void.

2fill in blank

medium

Complete the code to declare a FreeRTOS task function with the correct parameter type.

FreeRTOS

void vTaskCode([1] pvParameters) {
    // Task code here
}

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

Aint

BTaskHandle_t

Cvoid *

Dchar *

Attempts:

3 left

💡 Hint

Common Mistakes

Using a specific pointer type instead of void *.

The parameter for a FreeRTOS task function must be a void * pointer.

3fill in blank

hard

Fix the error in the task function signature to match FreeRTOS requirements.

FreeRTOS

[1] vTaskCode(void *pvParameters) {
    // Task code here
}

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

Avoid

BTaskFunction_t

CTaskHandle_t

DvTaskCode

Attempts:

3 left

💡 Hint

Common Mistakes

Using int as return type and returning a value.

The task function must return void, so change the return type to void and keep the function name as vTaskCode.

4fill in blank

hard

Fill both blanks to complete the FreeRTOS task function signature correctly.

FreeRTOS

[1] [2](void *pvParameters) {
    // Task code here
}

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

Avoid

BvTaskCode

CTaskFunction_t

DTaskHandle_t

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect return type or function name.

The correct signature starts with void as return type and the function name vTaskCode.

5fill in blank

hard

Fill all three blanks to complete the FreeRTOS task function signature and parameter correctly.

FreeRTOS

[1] [2]([3] pvParameters) {
    // Task code here
}

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

Avoid

BvTaskCode

Cvoid *

DTaskFunction_t

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong return type, function name, or parameter type.

The correct signature is void vTaskCode(void *pvParameters).

Practice

1.

What is the correct signature for a FreeRTOS task function?

easy

A. int TaskName(int param)

B. void TaskName(void *pvParameters)

C. void TaskName()

D. void TaskName(int *param)

Solution

1. Step 1: Recall FreeRTOS task function signature

   FreeRTOS tasks must have the signature with return type void and a single void pointer parameter.

2. Step 2: Match the signature with options

   Only void TaskName(void *pvParameters) matches void TaskName(void *pvParameters) exactly.

3. Final Answer:

   void TaskName(void *pvParameters) -> Option B

4. Quick Check:

   Task signature = void TaskName(void *pvParameters) [OK]

Hint: Task functions always return void and take void* parameter [OK]

Common Mistakes:

• Using int return type instead of void
• Omitting the void* parameter
• Using incorrect parameter types

2.

Which of the following is a syntactically correct FreeRTOS task function declaration?

void MyTask(_____)

easy

A. void *pvParameters

B. int param

C. char *name

D. void

Solution

1. Step 1: Understand parameter type for FreeRTOS tasks

   Task functions must accept a single parameter of type void *.

2. Step 2: Check each option

   Only void *pvParameters uses void *pvParameters, which is correct syntax.

3. Final Answer:

   void *pvParameters -> Option A

4. Quick Check:

   Parameter type = void *pvParameters [OK]

Hint: Task parameter must be void pointer (void*) [OK]

Common Mistakes:

• Using int or char pointer instead of void pointer
• Using void without pointer
• Missing parameter entirely

3.

What will happen if you run this FreeRTOS task function?

void ExampleTask(void *pvParameters) {
    for(;;) {
        // Task code here
    }
}

medium

A. The task will return a value causing runtime error.

B. The task will run once and then exit.

C. The task will cause a compile error.

D. The task will run repeatedly in an infinite loop.

Solution

1. Step 1: Analyze the task function loop

   The task contains a for(;;) infinite loop, so it runs repeatedly.

2. Step 2: Understand FreeRTOS task behavior

   Tasks should not return; they run inside infinite loops to keep running.

3. Final Answer:

   The task will run repeatedly in an infinite loop. -> Option D

4. Quick Check:

   Infinite loop in task = runs repeatedly [OK]

Hint: FreeRTOS tasks run inside infinite loops [OK]

Common Mistakes:

• Thinking task runs once and exits
• Expecting return value from task
• Confusing infinite loop with error

4.

Identify the error in this FreeRTOS task function:

void FaultyTask(void *pvParameters) {
    int count = 0;
    while(count < 5) {
        count++;
    }
    return;
}

medium

A. The function should not return; it must loop forever.

B. The parameter type is incorrect.

C. The variable count should be a pointer.

D. The while loop condition is invalid syntax.

Solution

1. Step 1: Check task function return behavior

   FreeRTOS tasks must not return; they should run inside infinite loops.

2. Step 2: Analyze the code flow

   This task loops 5 times then returns, which is incorrect for FreeRTOS tasks.

3. Final Answer:

   The function should not return; it must loop forever. -> Option A

4. Quick Check:

   Tasks must not return, use infinite loop [OK]

Hint: Tasks must never return; use infinite loops [OK]

Common Mistakes:

• Allowing task to return
• Changing parameter type incorrectly
• Misunderstanding loop conditions

5.

You want to pass an integer value to a FreeRTOS task. Which is the correct way to define and use the task function?

void NumberTask(_____)
{
    int received = *(int *)pvParameters;
    for(;;) {
        // Use received value
    }
}

hard

A. void pvParameters

B. int pvParameters

C. void *pvParameters

D. int *pvParameters

Solution

1. Step 1: Recall task function parameter type

   Task functions must accept a void * parameter to allow any data type.

2. Step 2: Understand data passing

   The integer is passed via pointer cast from void *, so parameter must be void *pvParameters.

3. Final Answer:

   void *pvParameters -> Option C

4. Quick Check:

   Use void* parameter to pass any data type [OK]

Hint: Always use void* parameter to pass data to tasks [OK]

Common Mistakes:

• Using int instead of void* parameter
• Using void without pointer
• Not casting void* to correct type inside task