Re: [ha] wired home network using CAN

Lars Wictorsson (
Thu, 26 Aug 1999 00:16:32 +0200

Hi Steve,

(so we CAN "lovers" meet here too ;-) )

I'm with you to a 100% and I also (as some might have read my
earlier posts) don't mind running seperate wires and use CAN,
since I have also worked with CAN since 1993 and just love

Right now I'm looking at the possibility to have a very
inexpensive node for this kind of purpose and it should
be able to update it through FLASH etc. I do not want to
go direct into the component selection I have made yet,
but it will be inexpensive per node.

I currenly use the C505C/C515C (an 8051 with CAN) and
also the stand alone CAN controllers SJA1000 and 82527.

This new node will be using the SJA1000, but I'm also waiting
for the first samples of the Microchip standalone CAN
controller MCP2510 or something like that. It is an SPI
18pin SOIC CAN controller.

With CAN it is also possible to run things like "intercom"
from one are in the house to the other, also have smart nodes
that operate for them self and send out info. e.g. an temp-
sensor can send out (without asking) the temp each second
and the CAN bus fic that with priority it self. then the
nodes who are interesting in that temp value catch that
message and use it, one could be a PC logging temperatures,
another a simple LCD for looking at the temp, another controling
heaters etc. CAN is very easy to deal with once you get
hang of it.


LAWICEL Phone : +46 (0)451-50750
Lars Wictorsson Fax : +46 (0)451-50750
E-mail: WWW :

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

> From: Steve Letkeman <>
> To:
> Subject: [ha] wired home network using CAN
> Date: den 25 augusti 1999 22:52
> Hi All,
> It's been so long since I subscribed to this mailing list
> that I'm not exactly sure what it's focus is on so if this
> thread is out of line than let me know.
> There is talk about power line modems, X10 and RS-485
> but I want to open another thread, and that is the use of
> CAN for hardwired home control. I am currently using X10
> for a few lights and find it just to slow and unreliable. I
> don't mind running wires if it gives me crisp response and
> reliability. RS-485 is a good choice because any micro
> can run an RS-485 port but since I spend all my professional
> time developing CAN devices, I'm very biased at this point.
> For those that don't know what CAN is, it stands for
> Controller Area Network and is a hardware device that
> is added to a number of micro's (internally or externally)
> that provides very, very robust communication over
> twisted pair cabling at speeds up to 1Mbps (40m max).
> The hardware looks after all the transfer of information,
> leaving the fun stuff for the user. This significantly reduces
> the software needed compared to RS-485 and allows
> a multi-master system. There are a number of low cost
> CAN micros including the Siemens C505C and various
> Motorola HC05's HC08's etc.
> I already have a number of CAN nodes running in my
> house monitoring and controlling various devices so I'm
> not really looking to start an argument over whether
> CAN should be used Vs. RS-485 because both have
> various pro's and con's, rather, this is a long winded
> attempt to find out if anybody is interested in developing
> a CAN based, open spec'd, home automation system.
> whew...done...
> comments?
> Steve Letkeman
> Zanthic Technologies Inc. located at
> Controller Area Network boards for HC11, ISA/PC104 and Parallel
> I/O boards for ISA and Parallel, Win95/98 and NT drivers included