RTOS on 8 bit controller...

simrantogether

Member

• Dec 30, 2007

• #1

Hi,

I wanted to start with my rtos work... to implement it on 8 bit controller...

I need five starting steps that is to be followed to implement RTOS... on any controller...

I'll be thankful...

Regards,

Simran..

 

atferrari

Well-Known Member

Most Helpful Member

• Dec 30, 2007

• #2

Five steps

Out of curiosity, how do you know they are exactly five?

 

simrantogether

Member

• Dec 30, 2007

• #3

I mean...

I mean any first five small steps to be followed...

Regards,

Simran..

 

felis

New Member

• Dec 30, 2007

• #4

You may want to start here -> http://www.picos18.com/index_us.htm

 

3v0

Coop Build Coordinator

Forum Supporter

• Dec 30, 2007

• #5

It would be better to get you hands on a book about RTOSes and OSes in general and read about them.

It is too complex a subject to use the N step method.

 

Nigel Goodwin

Super Moderator

Most Helpful Member

• Dec 30, 2007

• #6

For that matter why do you feel the need for an RTOS?, you're just diverting much of the micro-controllers resources to the RTOS and leaving less for the job you want to do.

 

P

Pommie

Well-Known Member

Most Helpful Member

• Dec 30, 2007

• #7

I find it hard to envisage a project where a RTOS would be useful on a microcontroller.

Mike.

 

S

Salgat

New Member

• Dec 30, 2007

• #8

Operating Systems allow for more portable code, and allow you to create a universal interface. I suppose for very complex tasks an OS can be useful.

 

3v0

Coop Build Coordinator

Forum Supporter

• Dec 30, 2007

• #9

A good RTOS will allow you to get the right code to run when needed with less effort on your part. The people who design them put a lot of time and effort into ensuring that it does. More than any firmware engineer can justify on a single project.

The downside, it is not a handcrafted solution, it will take more processor and memory. Like everything it is a tradoff, such resources are less expensive with time. Keep in mind that using an RTOS on a uC without enough headroom will always be bad.

We used PSOS to code at least one of our major product lines. There was support for PSOS (maybe others) in our debug toolchain which allowed customers to understand their code execution in terms of processes. That was over 15 years ago.

We all live in our little corner of the tech universe. I am thinking there is a lot of very real stuff out there that we may find hard to imagine.

 

simrantogether

Member

• Dec 30, 2007

• #10

Thanks...

Thanks...

I got to know the application of RTOS... and also the replies help me to understand the importance of them...

I wanted to one doubt:

1. if I know how to compile a program in C for a particular microcontroller and

2. if i know the basics of OS and RTOs and various RTOS commands like of ' free rtos ' then ...

3. what is the next step to be done... means how to embed that particular rtos into the controller and in what way...

For more information please see www.freertos.org

Regards,

Simran..

 

3v0

Coop Build Coordinator

Forum Supporter

• Dec 31, 2007

• #11

Look at the Quick Start Guide
Visit https://www.freertos.org/FreeRTOS-quick-start-guide.html
to download the source code and get started.

This download has working examples for many uC's.


Note:Run need at least 1536 bytes of RAM on a 18 series uC.

 

Mike - K8LH

Well-Known Member

• Dec 31, 2007

• #12

Simran,

Can you tell us some of the RTOS tasks you have in mind?

Mike

 

simrantogether

Member

• Jan 1, 2008

• #13

Well...

Well Mike,

I cannot say anything...

I just know some definitions in RTOS...

I am thinking of joining some classes for rtos...

Regards,

Simran..

 

Oznog

Active Member

• Jan 1, 2008

• #14

I don't get it either.
Microcontrollers do just fine handing different jobs by either the interrupt mechanism or:

Code:

initializeEverything();
while(1){
   if(buttonsNeedServicing)
       serviceButtons();
   if(uartNeedsFilling)
       fillUART();
   ...
   ...
} //and just loop this way forever

There is no "portability" issue, I have my portable tasks right here. I can move fillUART() to another processor or use it in a completely different program if it's written smart. Well if you go to a part that configures the UART differently, then fillUART() may need to be different- and the exact same thing should be true for an RTOS.

It's not just a matter of overhead, but for the above example it's just so clear what's going on. I never could see the need to bring in the issues associated with an RTOS.

 

Funny NYPD

New Member

• Jan 22, 2008

• #15

you should check the PUMPKIN RTOS, it is small and stable on PIC16s.
http://www.pumpkininc.com/