DalSemi 1-wire is useful for home automation projects: - cheap temperature sensors, switches, analog to digital convertors - uses a "1-wire" bus (data plus ground) - you can often "steal" power from the bus to power sensors (parasitic mode) - you can often do cable runs in excess of 100m easily, further if you use "MicroLAN couplers" or build 1-wire hubs I currently have 1-wire thermometors, barometric pressure, water level (hydrostatic), humidity, and light level sensors that I've built myself that communicate on 1-wire. http://www.dalsemi.com -marc On 5/6/03 08:57, "Hazelwood Lyle" wrote: >> From: Ruben vd Merwe [mailto:rubenv@AMPNET.CO.ZA] >> Subject: Re: [PIC]: Home Automation with PICs >> >> >> Thanks Lyle >> >> What are the possibilities for RS232 or 485? By the sounds of it I might >> have to go to a type of star config, as all my nodes will collaborate in >> one place. >> >> Ruben >> > -- > > Standard RS-232 is not addressable, though the "AUSART" in the > newer pics supports an addressing scheme. > > I have stretched RS-232 over much longer wires than are suggested, > but your mileage may vary. > > I have no experience with RS-485, but I believe the hardware layer > has many of the advantages you appear to be looking for. I do believe > it requires a driver chip. > > With RS-485, you can create a network of your design, but you are left with > creating all the details yourself. If this is what you want, great. > One reason I chose CAN is that most of the error detection, bus arbitration, > and other low level details are already done for me. I just set up the > necessary stuff and wait for messages that are pertinent to this node. > > I am not an expert on CAN. There are many on this list with far greater > experience than I. I am working towards knowing it better though. > If I have offered misleading or "wrong" information, I hope someone with > better knowledge will step in and offer a correction. > > I think your time will be well spent by reading more details on each of > the methods you are considering. The CAN system was designed by Bosch. > I'm sure a bit of time researching this with Google will provide you with > a great deal of information. > > There is a site "out there somewhere" that is a working community effort > to create a home automation system based on CAN controllers. I don't have > a link. > > The choices are all yours. There are many methods available, each with > advantages and disadvantages. It's up to you to evaluate them and decide > which best fits your needs and experience. I've offered about all I CAN > without interjecting too much personal opinion (I hope). > > Good Luck, > Lyle > > -- > http://www.piclist.com hint: To leave the PICList > mailto:piclist-unsubscribe-request@mitvma.mit.edu > > -------------------------------------------------- Marc Nicholas Geekythings Inc. C/416.543.4896 UNIX, Database, Security and Networking Consulting -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu