1.7 FreeRTOS Task Notification

This example application is to illustrate the FreeRTOS Task Notification feature which is used as a light weight binary semaphore.

Description

  • This demonstration creates two tasks that send notifications back and forth to each other.
    • Task2 blocks to wait for Task1 to notify and will be blocked for 500 ms
    • Task1 sends a notification to Tasks2, bringing it out of the blocked state, toggles an LED
    • Task1 blocks to wait for Task2 to notify
    • Task2 sends notification to Task1, bringing it out of the blocked state
  • Above steps will be repeated. i.e., an LED toggles for every 500 ms

Downloading and Building the Application

To clone or download this application from Github, go to the main page of this repository and then click Clone button to clone this repository or download as zip file. This content can also be downloaded using content manager by following these instructions.

Path of the application within the repository is apps/rtos/freertos/task_notification_freertos/firmware.

To build the application, refer to the following table and open the project using its IDE.

Project NameDescription
sam_9x75_curiosity.XMPLABX project for SAM9X75 Curiosity Development Board

Setting Up AT91Bootstrap loader

To load the application binary onto the target device, we need to use at91bootstrap loader. Refer to the at91bootstrap loader documentation for details on how to use it to bootstrap the application binaries.

Setting Up the Hardware

The following table shows the target hardware for the application projects.

Project NameDescription
sam_9x75_curiosity.XSAM9X75 Curiosity Development Board

Setting Up SAM9X75 Curiosity Development Board

  • Connect the UART DEBUG J35 on board to the computer using a UART-FTDI cable (to enable debug com port)
  • Connect the USB port J2 on board to the computer using a micro USB cable (to power the board)

Running the Application

  1. Build the application using its IDE
  2. The LED toggles on success for every 500 ms
Refer to the following table for LED name:
BoardLED Name
SAM9X75 Curiosity Development BoardRGB_LED (Green)