Recommendations for Room Temperature Sensors

[Bob Ober]

Mark Johannessen wrote:
> 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.
> 

1. the sensors can be daisy chained, they don't each need a separate wire.

2. The wire needs to be a two stranded twisted pair, common and signal.

3. Once the application on the Mac captures the data, a script can send 
the data to Xtension with a tell command.

4.  I used a program called portTerm to query the HA-7 and return the 
data from the sensors to an applescript script, which in turn wrote the 
data into Xtension.

5. I'm not really a programmer, so I'm not sure how one would capture 
the data and transfer it to Xtension from the web server, although I 
don't think it would be all that complicated.

6.  A good place to begin researching Macs and 1-wire temp systems is at 
either:

  http://www.aagelectronica.com/Weather/index.html

  or

http://timbitson.com/Weather%20Projects.html