Lpc2000

Hello,

You can try free RTOS.

http://www.freertos.org/


----- Original Message ----- 
From: "guillermoprandi" <yahoo.messenger@...>
To: <lpc2000@yahoogroups.com>
Sent: Thursday, October 06, 2005 3:21 PM
Subject: [lpc2000] Re: Low power multithreaded OS suggestion?


Thanks a lot. Looks very interesting. I'll look into it. However,
some preemptive multitasking is needed in my project since I must be
able to perform some lengthy calculations in one task while still
serving other tasks.

Guille

--- In lpc2000@yahoogroups.com, Marko Panger <marko.panger@s...>
wrote:
> Hi there,
>
> I just finished a project with the same problem. For the third UART
I've used a SW made uart via GPIOs and it works @ 115200 baud rate.
>
> As for the OS I used mine, uSmartX. The OS can inform you when
there is nothing to do (scheduler reurns SYS_IDLE) and I'm idling the
CPU at that point. My power consumption dropped for ~30%.
>
> If you want visit http://usmartx.sourceforge.net/ for more
information regarding the OS.
>
> Hope it helps,
> marko
>
> >
> > Od: "guillermoprandi" <yahoo.messenger@m...>
> > Datum: 2005/10/06 Èet PM 02:37:46 CEST
> > Za: lpc2000@yahoogroups.com
> > Zadeva: [lpc2000] Low power multithreaded OS suggestion?
> >
> > Hi! I am building a board featuring the LPC2138 ?C. This board
will
> > basically need to interface with three serial devices (two via
> > internal UARTs and a third via MAX3100, though suggestions are
> > welcomed about this). This device must be very low power; it
should
> > wake up only when needed, which is: 1) there's data available
from
> > any of the three ports, 2) there's data waiting to be transmitted
on
> > any of the ports and the port becomes free and 3) a periodical
> > overall check (every second or so). This means that theoretically
the
> > processor can enter the idle state quite often. I'm looking for
some
> > (free if possible) multithreaded OS that would handle the
transition
> > to the processor's idle state on traditionally blocking calls
like
> > fread() and fwrite(), expecting to wake up on interrupt; also,
some
> > preemptive multitasking should be supported, in case some thread
> > enters an exceptionally long calculating task. Probably there's
no
> > known OS that directly supports this; in this case, I'd like to
know
> > which other OS might be a good starting point to accomplish this
by
> > making the modifications myself. I'm aiming to use the GNU
libraries
> > (I ignore how difficult or messy would it be to modify them to
> > support this). Finally, it is my understanding that the VERY low
> > power "power down" mode would not be useful for my application,
since
> > the peripherals (therefore the UARTs and SPI) are shut down in
this
> > mode. Any advise or hint on these subjects will be greately
> > appreciated.
> >
> > Guille
> >
> >
> >
> >
> >
> >
> > Yahoo! Groups Links
> >
> >
> >
> >
> >
> >
> >
> >
> >






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