Lpc2000

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
> > 
> > 
> > 
> >  
> > 
> > 
> > 
> > 
> >