Task handle usage in FreeRTOS - Mini Project: Build & Apply

Task Handle Usage in FreeRTOS

📖 Scenario: You are building a simple FreeRTOS application where two tasks run concurrently. You want to create a task and keep its handle so you can manage it later, such as deleting or suspending the task.

🎯 Goal: Create a FreeRTOS task and store its handle in a variable. Then use the handle to suspend the task. Finally, print a message indicating the task was suspended.

📋 What You'll Learn

Create a task handle variable called Task1Handle

Create a task named Task1 with priority 1

Use xTaskCreate to create the task and store the handle in Task1Handle

Use vTaskSuspend with Task1Handle to suspend the task

Print "Task1 suspended" to the console

💡 Why This Matters

🌍 Real World

Task handles let you control tasks after creation, such as suspending, resuming, or deleting them. This is useful in embedded systems where tasks need to be managed dynamically.

💼 Career

Embedded software developers often use FreeRTOS task handles to manage multitasking in microcontroller applications, making this skill essential for real-time system programming.

1

Create a task handle variable

Declare a variable called Task1Handle of type TaskHandle_t and initialize it to NULL.

FreeRTOS

TaskHandle_t Task1Handle = NULL;  // Your code here

Need a hint?

Task handles are pointers used to refer to tasks. Initialize it to NULL before creating the task.

2

Create the task function

Write a task function called Task1 that takes a void *pvParameters argument and contains an infinite loop with vTaskDelay(1000 / portTICK_PERIOD_MS); inside.

FreeRTOS

TaskHandle_t Task1Handle = NULL;

void Task1(void *pvParameters) {
    // Your code here
}

Need a hint?

The task function must run forever, so use an infinite loop. Use vTaskDelay to wait 1 second each loop.

3

Create the task and store its handle

Use xTaskCreate to create the task Task1 with name "Task1", stack size configMINIMAL_STACK_SIZE, no parameters (NULL), priority 1, and store the task handle in Task1Handle.

FreeRTOS

TaskHandle_t Task1Handle = NULL;

void Task1(void *pvParameters) {
    for (;;) {
        vTaskDelay(1000 / portTICK_PERIOD_MS);
    }
}

// Your code here to create the task and store the handle

Need a hint?

Pass the address of Task1Handle to xTaskCreate to save the created task's handle.

4

Suspend the task and print confirmation

Use vTaskSuspend with Task1Handle to suspend the task. Then use printf to print "Task1 suspended".

FreeRTOS

TaskHandle_t Task1Handle = NULL;

void Task1(void *pvParameters) {
    for (;;) {
        vTaskDelay(1000 / portTICK_PERIOD_MS);
    }
}

xTaskCreate(Task1, "Task1", configMINIMAL_STACK_SIZE, NULL, 1, &Task1Handle);

// Your code here to suspend the task and print message

Need a hint?

Use the task handle to suspend the task. Then print the confirmation message exactly as shown.