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After a dilligent Web search, I am fairly convinced that no one has done something like what I am planning, so I submit this idea to the group for critique/analysis/humor/whatever What I would like to do is set up a network of temperature sensors in my 3-level house. These sensors would all communicate back to a master monitoring/logginf program on a PC. I had originally planned to go with wireless communication, but it seems that the basic serial wireless modules are still pretty expensive. I would like to keep the unit cost of the sensors down to around $10. So I am tentaively planning to use IR communication, and use the temperature sensors as transponders (?) to get the IR signal around corners, up stairs, etc. I have heard that IR for data communication can be flaky over larger distances, so I would like to hear if anyone has had great success with this. I could probably luve with a 10' range if I had to. One I get the communication network set up, I think developing the protocol will be the fun part.. :-) Any suggestions welcome. The neat thing about talking to a group like this is that I don't have to explain WHY I want a network of temperature sensors set up around my house.... :-) Alex

Hello Alex, First of all, WHY do you want the temperature sensors??? Just kidding. I'm doing the smae kind of project, only not only wwith temp. sensors, but a lot of other things, something like home automation. There are severql cheep wireless transmitters and recievers on the market, see linxtechnologies (http://www.linxtechnologies.com) TX == $11.00 RX = $5.00, or the other way around. What i am going to do is the following, 1 master system, with lcd, RX and TX, keypad and a 68hc11 or Pic. In every rom 1 system with a TX and RX pair and a pic and IR. In my hous i can do this because if i hang my pic in a good place i can make contact with all other devices with an IR link. 1 System in my car 1 System in my garage 1 system in the garden 1 System connected to my computer All the systems talk to eachother with a token ring protocol, because you don't want them all to send at the same time. and token ring is fast enaugh at 4800 bps. On my remote system i can control all nodes, water my plants, turn on the heating, turn on the waterfall in the garden etc. On the computer i can log all activities etc. Hope this helps Richard Meester Software Engineer spam_OUTAlexkTakeThisOuTCONCENTRIC.NET wrote: {Quote hidden}> > After a dilligent Web search, I am fairly convinced that no one has done > something like what I am planning, so I submit this idea to the group > for critique/analysis/humor/whatever > > What I would like to do is set up a network of temperature sensors in my > 3-level house. These sensors would all communicate back to a master > monitoring/logginf program on a PC. I had originally planned to go with > wireless communication, but it seems that the basic serial wireless > modules are still pretty expensive. I would like to keep the unit cost > of the sensors down to around $10. So I am tentaively planning to use > IR communication, and use the temperature sensors as transponders (?) to > get the IR signal around corners, up stairs, etc. I have heard that IR > for data communication can be flaky over larger distances, so I would > like to hear if anyone has had great success with this. I could probably > luve with a 10' range if I had to. One I get the communication network > set up, I think developing the protocol will be the fun part.. :-) > > Any suggestions welcome. The neat thing about talking to a group like > this is that I don't have to explain WHY I want a network of temperature > sensors set up around my house.... :-) > > Alex

Alex, As always on the Internet your not alone to want to do crazy things. ;-) Me to have thoughts in this direction. After a lot of tests and a lot of thinking ( OK some anyway...) I have decided to use the 1-Wire bus for my control network as it gives me a very low cost for each node. For a node where I just need to read the temperature I can use a DS-1820 the cost for the node is about $5 ) and at nodes where I need a sens of some digital data or want to switch something I can use a DS2405 (node cost $3). Added to this is of course the cost for the cable. I have decided to use CAT 5 twisted pair but any telephone grade twisted pair cable should do. The better the cable more devices and more length can be added to the network. I have some nodes where I need to do some more things for instance a unit that warms he water in the house and a unit that fills pellets in a stoker and warms up my house. Previously these units have been controlled by RS-232 links but will soon be ( I hope ) slave devices on the 1-Wire bus. In my opinion is the 12C50X and all the other PIC controllers perfect as slave devices. The makes it possible for me to have intelligent nodes with the lowest possible cost for each node. At the moment I am working on the slave protocol and will publish this code here as soon as it's stable enough. There is only one problem with this and that is that I have to come up with my own serial number system. As you probably know a device on the 1-Wire bus is identified by a 6 byte number consisting of a 1-byte family code, a 6-byte serial number and a 1 byte crc making a globally unique number. So if I come up with a family code and a serial number of my own there is at the moment no way for me to be sure it is globally unique. I have suggested to Dallas to put a side a family code for use much the same way as the 192.168 net is used on the internet. If this family code was set a side it would be possible for me and others to produce devices using our internet address as the first three bytes and use anything else in the remaining bytes and be shure that its globally unique. Also this would make it possible to use 192.168 in the first byte for internal systems where no other units from other manufacturers will be used. But as Dallas makes circuits that provide this functionallity I guess the will not follow this suggestion . :-) BTW I also use a PIC to i/f a PC which controls the network. This device communicates to the PC through a serial port using high level commands to do things on the 1-Wire bus such as Match Rom, Find all Rom devices, Alarm Search etc etc. It uses a 16F84 and removes the burden from the PC to handle all the bits and pices of the 1-Wire protocol. There is also no need to buy the SDK from Dallas... This code will be available on http://neon.eurosource.se very soon. Regards /Ake ====================================================================== Ake Hedman - Soft.Dev.Eng. Eurosource, Gruvbyn 415A, S-820 50 LOOS, SWEDEN Phone: +46 657 413422 Fax: +46 657 10612 WEB: http://www.eurosource.se Carpe diem quam minimum credula postero ====================================================================== > {Original Message removed}

Hello Richard meester, on 11-Ago-98 15:04:00, you said, >All the systems talk to eachother with a token ring protocol, because >you don't want them all to send at the same time. and token ring is fast >enaugh at 4800 bps. Hhmm...where I can find more info about making a token ring network with PIC16c84? have you got some docs? Let me know, thanks! --- Alessandro Marzini Amiga Group Italia - LIVORNO ------------------------------------------- Email a.marzini A3000T PPC604@233 040@40 78Mb RAM Phone 0347 7687788 Rom 3.1 Super Buster 11 Cybervision 64 3D - Peggy Plus - PhonePak GVP - DKB4091 Scanner Epson GT-9000 - CDR Plexwriter 4/12 CDROM Plextor 12x - ZIP 100Mb - USR 33.6K Epson Stylus Color 500 - 2 HD SCSI 1Gb ------------------------------------------- --

Hello Alessandro, The protocol is really simple, i dont have any docs, its something i just going to implemented myself. The easiest way is to let everybody be silent during startup. And let the master sent a token (i.e. a 2 or 4 byte header followed by data if there is any. in the worst case probably all nodes recieve this message, but only the next node id in line (i.e. 2) does something with the message. In the header of the message the dest ID is set, sso if the dest id is not the current node id, retransmit the message to the following node. the following node (i.e. 3) will hear this message and does the same. When the dest node is reached, this node gets the data and sents the empty node to the following node. etc. So if nbobody has data to sent the only thing that goes around is an empty token. When an empty token is reached by a node who does want to sent data, it sets all items in the node header, attaches the data, and transmits the token. Hope this clarifies, regards richard Meester. Alessandro Marzini wrote: {Quote hidden}> > Hello Richard meester, on 11-Ago-98 15:04:00, you said, > > >All the systems talk to eachother with a token ring protocol, because > >you don't want them all to send at the same time. and token ring is fast > >enaugh at 4800 bps. > > Hhmm...where I can find more info about making a token ring network with > PIC16c84? have you got some docs? Let me know, thanks! > > --- > > Alessandro Marzini Amiga Group Italia - LIVORNO > ------------------------------------------- > Email a.marzini A3000T PPC604@233 040@40 78Mb RAM > Phone 0347 7687788 Rom 3.1 Super Buster 11 > Cybervision 64 3D - > Peggy Plus - PhonePak GVP - DKB4091 > Scanner Epson GT-9000 - CDR Plexwriter 4/12 > CDROM Plextor 12x - ZIP 100Mb - USR 33.6K > Epson Stylus Color 500 - 2 HD SCSI 1Gb > ------------------------------------------- > > --

On Sat, 22 Aug 1998, you wrote: >Remove me from your list for now >thk There is no-one on the list who can remove you from the list, (Jory excepted). You must do it yourself. Send an email to: .....listservKILLspam@spam@mitvma.mit.edu, with the message signoff piclist in the BODY of the message, the subject is unimportant. Don't put any stuff in the message body. The List server will try to interpret them commands. This must be sent from the email address that was used when you originally subscribed to the list. This is to authenticate the request. Good Luck with the electric vehicle stuff. regards, -- Ray Gardiner rayKILLspamhdc.com.au