Recommendations for Room Temperature Sensors

[Mark Johannessen]

On 1/2/07, Bob Ober <rmober123 at comcast.net> wrote:

> My controller is an HA-7E, and I am using a Keyspan USA-19H USB to
> Serial converter.  Neither has given my any problem other than taking a
> while for the HA-7 to show up and start responding the first time.
>
>   There is another HA-7 which can be connected by ethernet which I have
> not taken a close look at.

Its called the HA7Net - Ethernet 1-Wire Host Adapter (see
http://www.embeddeddatasystems.com/page/EDS/PROD/HA/HA7Net).    The
literature states:

"The HA7Net supports a variety of 1-Wire devices at a high level.  For
example, reading the current temperature from a DS18S20 doesn't
require the user to learn the details of reading and parsing
scratchpads.  Instead, you simply ask the HA7Net for the current
temperature and it handles all of the required low-level
communications for you ..."

and

"Primary communication with the HA7Net is accomplished via the HTTP
protocol, with optional 128 bit SSL data encryption.  The actual data
is exchanged in the form of html documents which have been designed to
accommodate both human readability and 100% reliable machine parsing.
This is accomplished through the use of unique, predictably named form
fields that can be automatically parsed by most DOM parsers, or easily
digested via regular expressions on lighter weight platforms. Data is
passed to the HA7Net in the form of parameters placed in the URL.
Since the result pages are human readable, both proof of concept and
integration times are reduced as you can effectively interact with
1-Wire devices via the HA7Net using a standard web browser."

The document goes on to show an example of 100 sensors per HA7Net.

So, if I'm reading this correctly, one can use up to 100 1-Wire
sensors wired to a HA7Net each with a single wire (that would also
power the sensors), and the HA7Net will report the status of each
sensor via the HA7Net's built in web server based on commands sent to
it in the url.

The next question is how to access the sensor data and use it in X4X.
It appears that a serial data acquisition device (like the Keyspan
USA-19H USB to Serial converter you referred to) is not necessary and
data acquisition can be done via the ethernet connection between the
HA7Net and the Mac, and by parsing the returned html pages after a url
command is sent.

Any thoughts on this?

Mark J.