Subject: From: Date:

RE: [ECS] iButton/1-Wire Interface David Kindred Mon, 13 Nov 2000 08:02:41 -0500

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Nathan,

What did you need in the way of hardware to interface with the 1-Wire items?
In other words, what's the start-up cost?

Sure sounds interesting!

--David

-----Original Message-----
From: Nathan Brown [mailto:nbrown@thystonius.com]
Sent: Sunday, November 12, 2000 2:22 PM
To: ECS UserList (E-mail)
Subject: [ECS] iButton/1-Wire Interface


I'm glad to hear there is some interest.  I'll try and answer everyones
questions.

More about the software:
The software was written in VB and provides an interface that retrieves
all items from ECS then allows any item to be linked to the 1-wire
network.  There are two basic types of "links" that the software
currently supports.  For those of you who are not familiar with 1-wire
technology it is based around a digital serial number that is guarenteed
unique.  Every 1-wire device has one of these serial numbers.  Ever time
a device is added to or droped from the network the software sends that
serial number and action code to any item in ECS.  This is usefull for
user authentication.  "If this ibutton is not on the network then don't
disarm the security system".  The second type of connection is by a
message from a specific device.  In this case one ECS item is linked to
once 1-Wire device and the state of the item is updates with the state
received from the device (such as a temp prode) at a selectable
interval.

At the moment the only 1-wire devices supported are:
Any iButton (only the 64-bit ROM is read)
Any temperature probe and temperature iButton

There are many 1-wire devices out there including:
Preseusre sensors
A2D Converters
Relays/Switches
Digital Inputs
RAM
Timers
PH Sensors
...

Currently the software only supports either a parallel or serial port
connection.   I am learning more about the USB interface now.
More technically:
I have only tested the software using the DS1410E and DS9097U
interfaces, but I suspect the other will be no different.

All this information can be found at Dallas's Web site
www.dalsemi.com or specifially for iButtons www.ibutton.com
A good distributor for addtional parts is Point Six www.pointsix.com

At point six you'll find digital temp sensors for under $6 and 2 channel
Digital I/O for $10

My next more with the software is to start making it a little more user
friendly and beefing up the UI.

Nathan

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