Lpc2000

David Hawkins wrote:

>
> > I can however recommend the chip. Easy to work with.
>
> Good to know.
>
> > I am about to do a reference implemention of VSCP on the LPC-2129 and
> > this is my first work with CAN on the LPC family. But if CAN works as
> > well as other parts of the chip this should not be a big problem. The
> > LPC family is definitely becoming my favorite.
>
> What is VSCP?

It stands for Very Simple Control Protocol and *is* "a very simple" HLP 
for CAN. Info here http://www.vscp.org  Mainly constructed for SOHO use 
but is also used in many data acquistion systems.

>
> I haven't worked with any of the CAN bus interfaces used here.
> I have heard complaints that the XAC3 has a hard time keeping
> with a 1MB/s CAN bus.

With back to back frames at 1MB/s I think a SPI device is out of the 
question. This is hard as it is anyway.

>
> How's your, or anyone else reading this, experience been with an
> LPC CAN device? What kind of CPU loading can be expected
> for a device having to transfer say a few hundred bytes every
> half-second during normal operation, but say several thousand
> messages-per-second in a debug mode (eg. acting like a data
> acquistion device a 1KHz sample rate).
>
> With the DSP work I've done, I use the uCOS-II RTOS. I've got a
> port running on the LPC devices, and I have the port correctly
> nesting interrupts (which none of the Micrium web site uCOS-II
> ports do). I figure when I implement the CAN interface to the
> encoder, I'll build on that work.

I haven't had any real hands on experience with CAN on the LPC so I pass 
this for now. But I guess it depends primarily on what post processing 
you will do on the CAN frames. Would have been nice to here from others 
who have done some real work on CAN & LPC what they think about it in 
general.


>
> > Impressive site you work at BTW.
>
> Its a fun place to work and live, but very dependent on NSF
> funding. We just lost 15% of our required budget due to NSF
> cuts, and that resulted in a number of people losing jobs.
> This unfortunate situation is one reason why I need to start
> learning more about the CAN bus.
>
Funding is a hell. One of my best friends work as a professor in physics 
and funding and (other) paperwork is 90% of his time. But I guess its 
somewhat the same for us in the private business as well. Hunting 
contract work... ;-)

Which HLP are you using for CAN. DeviceNET or CANOpen or something you 
put together yourselves?

Cheers
/Ake

-- 
 ---
Ake Hedman (YAP - Yet Another Programmer)
eurosource, Brattbergavägen 17, 820 50 LOS, Sweden
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