RTOS for Dummies like me

RTOS for Dummies like me

  • Hi all,

    RTOS seems to be doing rounds nowadays. For
    understanding the rtos i read some books, browsed in rtos sites
    such as freertos.org, ucosII, etc. Read books to understand
    concepts such as preemptive kernel, semaphores etc.,. But, still I
    am totally unaware of how to implement an RTOs, may be definitely
    due to my ignorance.




    1. Is an rtos a set of library functions which have to be called at
    appropriate places in the code to create tasks, maintain timing
    etc.?


    2. Let's say I have a code of a timer used with a 8 bit timer and
    display the time in the LED 7 segment display. where will this rtos
    code reside and how will it interface with my code?


    3. How is it practically done.




    Can someone throw some light on this please?




    Regards




    Vasan












  • Do you have a MCU platform you can use to try out some code?
    Sometimes just trying out a "test" application can help you to
    understand.


    There's several code projects to start with that can teach about
    the concepts. The book by Jean Labrosse at Micrium is very good.
    He's also published several "ready to run" projects that work on
    our development boards.


    Off the top of my head, I think we have H8 and M16C projects
    with Micrium, XMK and uExec (which is a preemptive scheduler).



  • Previously Jayaraman.K.Vasan wrote:



    Hi all,

    RTOS seems to be doing rounds nowadays. For
    understanding the rtos i read some books, browsed in rtos sites
    such as freertos.org, ucosII, etc. Read books to understand
    concepts such as preemptive kernel, semaphores etc.,. But, still I
    am totally unaware of how to implement an RTOs, may be definitely
    due to my ignorance.




    1. Is an rtos a set of library functions which have to be called at
    appropriate places in the code to create tasks, maintain timing
    etc.?


    2. Let's say I have a code of a timer used with a 8 bit timer and
    display the time in the LED 7 segment display. where will this rtos
    code reside and how will it interface with my code?


    3. How is it practically done.




    Can someone throw some light on this please?




    Regards




    Vasan











    There is an RTOS available for the EDK38024, which
    has a 7-segment x 4 segments display. The RTOS is called uC/OS-II
    and is free for non-profit/academic uses.
    http://www.micrium.com/downloads/appnotes/EDK38024-uCOS-II.ZIP
    ...contains the entire RTOS in source code and an SRECORD file that
    can easily be flashed onto the board that demonstrates the RTOS
    running and data output on the display. Check with Renesas about
    how to obtain an EDK38024 board. Take Care. Rob!

  • Previously Jayaraman.K.Vasan wrote:



    Hi all,

    RTOS seems to be doing rounds nowadays. For
    understanding the rtos i read some books, browsed in rtos sites
    such as freertos.org, ucosII, etc. Read books to understand
    concepts such as preemptive kernel, semaphores etc.,. But, still I
    am totally unaware of how to implement an RTOs, may be definitely
    due to my ignorance.




    1. Is an rtos a set of library functions which have to be called at
    appropriate places in the code to create tasks, maintain timing
    etc.?


    2. Let's say I have a code of a timer used with a 8 bit timer and
    display the time in the LED 7 segment display. where will this rtos
    code reside and how will it interface with my code?


    3. How is it practically done.




    Can someone throw some light on this please?




    Regards




    Vasan








    You can access my thesis at this link:




    http://www.alessandrocasoni.it/polverari.html


    sorry but is only in italian.


    I've worked with Micrium for Renesas Starter Kit SH2A 7201.


    In Appendix there's all C code.


    Control Task, semaphore, Communication Task, ADC, MTU2
    (pwm)...


    Ciao from Italy


    massimo



  • Our RTOSes  called DSPnano for 16 bit processors and Unison
    for 32 bit processors offer complete explanations of how they
    should be used and 20 or so out of the box and running examples for
    each processor port.   There is a number of Unison ports
    and one DSPnano port in the works.  They offer a tiny tiny
    embedded Linux or POSIX compatible RTOS without GPL.



    http://rowebots.com/products/unison


     



    http://rowebots.com/products/dspnano


     



    http://rowebots.com/Embedded_Processor_support/renesas_m16c_development


     



    http://rowebots.com/Embedded_Processor_support/renesas_H8SX


     



    http://rowebots.com/Embedded_Processor_support/renesas_R32


     


     


    And the documentation is on line here:


     



    http://rowebots.com/downloads/DSPnano_Tutorial_GuideE8sec.pdf



    http://rowebots.com/downloads/DSPnano_Programmers_Guide_E1sec.pdf



    http://rowebots.com/manpages/help_index.html


     


    or


     



    http://rowebots.com/downloads/Unison_Tutorial_GuideE5sec.pdf



    http://rowebots.com/downloads/Unison_Programmers_Guide%20E3sec.pdf


     


     


    Please contact us for any clarification of any items.


     


    Kim