1 / 20

Design and realization of experiments for an embedded Linux Laboratory class

Design and realization of experiments for an embedded Linux Laboratory class. Ciaran mc Girl 4 th Electronic and Computer Engineering Project Presentation April 2008. Topics:. Brief Project Overview Real Time Systems RTAI Experiments Documented Problems Encountered Future development

travis
Télécharger la présentation

Design and realization of experiments for an embedded Linux Laboratory class

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Design and realization of experiments for an embedded Linux Laboratory class Ciaran mc Girl 4th Electronic and Computer Engineering Project Presentation April 2008

  2. Topics: • Brief Project Overview • Real Time Systems • RTAI • Experiments Documented • Problems Encountered • Future development • Questions

  3. Brief Project Overview: -Set up a workingset of real-time laboratory exercises,togetherwith proper documentation, a supportingsoftware infrastructure andsome Guidelinesfor laboratory supervisors. -Experiments vary from running a single task program to a task with a variable period.

  4. Real-time Systems A real time system is where its application is considered to be mission critical, with a set deadline in which to be completed, if the application misses it’s deadline then it’s said to have failed Hard Real-time Systems Soft Real-time Systems

  5. RTAI – Real Time Application Interface RTAI is not a real time operating system but instead takes priority over Linux at low level and in doing so leaves Linux as a low priority task so it cannot interrupt the RTAI.

  6. RTAI - How It works: Consists basically of an interrupt dispatcher, mainly traps the peripherals interrupts and if necessary re-routes them to Linux; using the concept of HAL (Hardware Abstraction Layer) kernel kernel RTAI Hardware Hardware

  7. RTAI Installation • Download a new kernel and the RTAI • Patching this kernel with the RTAI • Compile and install the kernel • Documented for student installation

  8. Experiments Documented • Single Periodic Task • Periodic scheduling of two tasks • Variable Period Task

  9. Single Periodic Task • Single Task using a set period • Toggles the PC speaker, emits a tone using Pulse width modulation

  10. Single Periodic Task Contd. • Laboratory Session Developed • Initialise a task • Name a task • Remove a module

  11. Periodic Scheduling of Two Tasks • Two tasks that run at two different periods • One task toggles the PC speaker every 100ms like the first experiment with the addition of having to decrement a variable before each toggle. • The other task runs every second and increments the variable used by the first task. • This increases the time between toggles and causes the tone to lower.

  12. Periodic Scheduling of Two Tasks Contd. Laboratory Session Developed • Working with the original experiment, develop another task to increase the delay between the toggles (using a shared variable)

  13. Variable period Task • Uses One-Shot mode • Task runs until completion • A delay is incremented and decremented and so the tone from the PC speaker is increased and decreased repeatedly.

  14. Variable period Task contd. Laboratory session developed • Introduce the students to one shot mode and how the task operates. • The students must then incorporate the delay for the task to sleep.

  15. RTAI-Lab • XRTAILAB - GUI Included with the installation of RTAI • Scilab (open source MATLAB Equivalent) with a Scicos extension. • Then RTAI-Lib extension is added to Scicos • Various other Installations including Mesa

  16. RTAI-Lab contd. Sine Wave example

  17. Problems Encountered • 64 bit Architecture • AMD Processor • Ubuntu Distribution of Linux • Mesa library problems

  18. Future Development • More Documented Experiments • Remove any “teething” problems with current documented ones. • The RTAI-Lab could be used to help students with the understanding of real-time programming with the visual aid of the blocks in the system.

  19. Questions?

More Related