Hi,

(first sorry if this is a bit of the topics)

> Looking for some input on using the CAN (Controller Area Network)
> protocol.
> Is anyone out there using this interface in real world applications?
> Would
> it be useful for a student / engineer / tech to learn how and where to
> use
> this protocol with an embedded micro?  Anyone with any feedback on this
> possibility.  I have already included the RS-232 and RS-485 interfaces on
> the board.

We have used CAN since 1993 and I personally like it very much. As you
might now CAN was first developed for cars, to reduce cable/weight
inside the cars, but it gain popularity in the industry as well for
smart distributed system.

If you surf over to http://www.lawicel.com/e_links_can.htm you
will find some links to CAN related sites, there is also info
on how to join the CAN discussion forum. Check Mike Schofield's
site with great CAN info.

We have used the Siemens/Infineon C515C and C505C with integrated
CAN (8051 compatible), the Siemens/Infinieon C167 (16bit) with
integrated CAN controller. Then 82C200 stand-alone CAN controller
which was discontinued 2 years ago and replaced with SJA1000. These
are from Philips. The also have an 8051 derivative with CAN (592),
but it can only handle the 11bit IDs, not the CAN2.0B standard
with 29bit IDs. Philips were supposed to discontinue that too, but
all users complained and they only discontinued the 598 with OTP.

Then Intel has the "original" CAN controller 82527 with parallel
or SPI port. This controller also has some spare ports that can
be used for I/O. Nice controller to use with SPI.

Siemens/Infineon also has stand-alone CAN controllers and Microchip
has announced a stand alonce CAN controller which should come
on the market within weeks/months. It is a 18pin DIP/SOIC with
SPI interface, looks promizing for small systems.

If you have a microcontroller today that you like and use and want
to add CAN, I would select SJA1000 if you have a parallel interface
with databus or 82527 if you have a small controller and want to
use it with SPI. Note however since CAN can go up to 1Mbit, you
will load the microcontroller a lot if you have high bus load
since you have to fetch/send the frames via the SPI port!

I hope this will help and if not, do not hesitate to e-mail me
for further information.

Regards

/Lars

P.S. Right now I'm evaluating the AVR with a stand-alone
CAN controller and also waiting for the Microchip samples
for their CAN controller.

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LAWICEL                    Phone  : +46 (0)451-50750
Lars Wictorsson            Fax    : +46 (0)451-50750
E-mail: lars@lawicel.com   WWW    : http://www.lawicel.com

Embedded hardware/software together with 8051/C16x/AVR and
smart distributed I/O with Controller Area Network (CAN).
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