8-bit MicrocontrollersのトピックRe: RTOS required for QG8 microcontroller

RTOS required for QG8 microcontroller

sagar — Wed, 31 Oct 2007 20:36:37 GMT

Hi,

I need help on QG8 RTOS. Is there any free RTOS available for QG8?

Thanks

Sagar

Re: RTOS required for QG8 microcontroller

tonyp — Wed, 31 Oct 2007 21:38:44 GMT

Usually, for such small chips, the need for an RTOS is easily bypassed by using interrupts (like RTI) or other simpler-than-RTOS solutions that emulate basic multitasking, because (by considering code size alone) an application doesn't have enough room to get overly complex, anyway. In some situations, however, even with such small chips, an RTOS is the only reasonable way to go.

You migh elicit more responses if you add some information, like:

Do you use C or assembly (some RTOS are tailored to C coders, others to assembly fans), do you need a pre-emptive or co-operative RTOS?

Are you happy with plain round-robin, or must you have priority-based?

How many tasks do you expect to run at once?

What basic features do you expect it to have, as minimum?

Regardless, with the QG8 being rather limited memory-wise (RAM in particular), only a handful of RTOS will be able to even begin to run under it (and these not fully loaded, of course).

What size do you expect your application alone to be (RAM/ROM), without the RTOS, but considering its presense which in most cases reduces main application size?

Since I have been using my own RTOS exclusively (not free to anyone but my highness), I haven't tried any of the free ones lurking around, but you might want to start by giving FreeRTOS a try, mentioned in this thread.

Hope this helps.

Re: RTOS required for QG8 microcontroller

sagar — Wed, 07 Nov 2007 16:55:40 GMT

Hi tonyp,

Yes I wanted to give a try to the thread you mention. For me C or assemly any language is OK. But prefrence is for C if it memory permits. I need preemptive RTOS. Simple round robin is OK & I expect 2 to 3 tasks running.

Right now I am not looking for any application. I first just want to toggle pin using RTOS. First I want to port the basic RTOS then based on the memory I will try to fix any small application on it.

Please help me you have ready code for this?

Regards

Sagar

Re: RTOS required for QG8 microcontroller

thm59 — Sun, 11 Nov 2007 01:25:27 GMT

Hell,

I confirm that HELIUM ( helium.sourceforge.net ) works fine with MC9S08QG8

I attach a CodeWarrior exemple with helium. It includes 2 tasks toggling 2 leds (PTBD6 & PTBD7) at different speed. It can be used on DEMO9S08QG8.
The TBM is used for scheduling.

thierry

PS:I assume no responsability with the use of this code

Re: RTOS required for QG8 microcontroller

HarrySun — Tue, 13 Nov 2007 00:27:21 GMT

hi, Thierry,

thanks for the code.

I tried on demo board, but the leds are not toggling.

when it was compiled ,it warned the project .map is missing, does it matter?thanks

Re: RTOS required for QG8 microcontroller

joerg — Tue, 13 Nov 2007 02:33:03 GMT

Hi
a very simple OS is the EBS08. The version for the QB8 can be downloaded here:

www.systech-gmbh.ch/ebs08/indexEBS08.html

The QB8 version is written in "C" and needs only 115 bytes of ROM and 4 bytes of RAM!

Saluti Joerg

Re: RTOS required for QG8 microcontroller

thm59 — Wed, 14 Nov 2007 04:55:24 GMT

Hello Harry,

Are your board jumpers correctly set?
I just tried it on my DEMO9S08QG8 board and it works as expected.

You can also make a "full chip simulation" : if you place a breakpoint on the 2 lines toggling PTBD6 and PTBD7, you will see that PTBD7 is toggled 4 times when PTBD6 is toggled once.

thierry

PS: I saw just that a new version (1.2) of Helium was released.

Re: RTOS required for QG8 microcontroller

HarrySun — Tue, 04 Dec 2007 04:49:05 GMT

Thierry,

thanks very much for your reminder,indeed my jumpers'setting was wrong.

now it's working .