Priority numbering in FreeRTOS - Mini Project: Build & Apply

Priority numbering in FreeRTOS

📖 Scenario: You are working on a small embedded system using FreeRTOS. You want to understand how task priorities are numbered and how to set them correctly.

🎯 Goal: Learn how to define task priorities using FreeRTOS constants and create tasks with specific priority numbers.

📋 What You'll Learn

Create a variable for the maximum priority using FreeRTOS constant

Create a variable for the minimum priority using FreeRTOS constant

Create a task with a priority between minimum and maximum

Print the priority values to verify

💡 Why This Matters

🌍 Real World

Embedded systems often use FreeRTOS to manage multiple tasks with different priorities to ensure important tasks run first.

💼 Career

Understanding task priority numbering is essential for embedded developers working with real-time operating systems like FreeRTOS.

1

Define FreeRTOS priority constants

Create two variables: max_priority set to configMAX_PRIORITIES - 1 and min_priority set to 0.

FreeRTOS

# Define max_priority and min_priority variables
# Your code here

Need a hint?

FreeRTOS priorities start at 0 for the lowest priority and go up to configMAX_PRIORITIES - 1.

2

Set a task priority between min and max

Create a variable task_priority and set it to the middle priority between min_priority and max_priority using integer division.

FreeRTOS

max_priority = configMAX_PRIORITIES - 1
min_priority = 0
# Set task_priority to the middle value between min_priority and max_priority
# Your code here

Need a hint?

Use integer division // to find the middle priority.

3

Create a FreeRTOS task with the chosen priority

Write a line to create a FreeRTOS task called vTaskExample with priority task_priority. Use the function xTaskCreate() with parameters: vTaskExample, "ExampleTask", 1000, NULL, task_priority, NULL.

FreeRTOS

max_priority = configMAX_PRIORITIES - 1
min_priority = 0
task_priority = (max_priority + min_priority) // 2
# Create a FreeRTOS task with xTaskCreate and task_priority
# Your code here

Need a hint?

Use xTaskCreate() with the correct parameters to set the task priority.

4

Print the priority values

Write three print() statements to display min_priority, task_priority, and max_priority with descriptive text.

FreeRTOS

max_priority = configMAX_PRIORITIES - 1
min_priority = 0
task_priority = (max_priority + min_priority) // 2
xTaskCreate(vTaskExample, "ExampleTask", 1000, NULL, task_priority, NULL)
# Print min_priority, task_priority, and max_priority
# Your code here

Need a hint?

Use print() with f-strings to show the priority values clearly.