In article <(E-Mail Removed) t>, msg <msg@_cybertheque.org_> wrote:
>LR wrote:
>> On 07/07/2009 17:20, Jeff Liebermann wrote:
>>> On Tue, 07 Jul 2009 13:28:18 GMT, (E-Mail Removed) (Rico) wrote:
>>>
>>>> I know odd question but has anyone seen or run across an wifi (g)
>>>> thermometer that can be accessed via a LAN or for that mater an IP
>>>> thermometer? Plenty of wireless ones via Google but have a need to place
>>>> one outside and have it readable from the LAN if possible.
>>>
>>> Expensive:
>>> <http://www.omega.com/toc_asp/subsectionsc.asp?book=DAS&subsection=K01>
>>>
>>> Only one temperature? If so, then it's much easier to communicate the
>>> temperature using one of the cheap consumer 49MHz wireless sensors to
>>> a base unit that has ethernet, than to do all the processing outdoors,
>>> and communicate the results via wireless. For example, the typical
>>> wireless thermometer runs on two AA batteries and runs for 2 years. A
>>> Wi-Fi link will require far more power to operate. Search for
>>> wireless weather stations with ethernet:
>>
>> I have had a couple of Oregon Scientific weather stations in the last 10
>> years and while the base stations have been reliable the remote Temp
>> sensors have never lasted. I have used the 418MHz and 433MHz versions
>> and had problems with:-
>> 1. Range, should be about 30 metres but due to the location of the base
>> stations have never got more than 10 metres.
>> 2. Min Temp, according to the manual the "proposed operating range" was
>> -5C to +50c and on a frosty morning I would lose the indication on the
>> base station and you had to wait for the temp to increase and you would
>> then have to force the base station to do a search to get the remote
>> sensor to synchronise.
>> 3. Sensors were prone to failure when being knocked, squirrels and birds
>> used to tap one of the sensors and I on a couple of occasions hit one
>> moving ladders in the garage eventually causing it to fail.
>> 4. Performance of the remote sensors degraded over time such that after
>> about 15 months I had to place them on the outside wall of the house as
>> they had virtually no range.
>> 5. The 433MHz sensors were prone to interference from everything from
>> car alarm remotes to wireless bell pushes.
>>
>> After having about 8 remote sensors I have eventually given up on them.
>
>In light of issues with simple radio telemetry sensors, I mention FWIW
>a simple WiFi solution that has been proven by years in the field: Ken
>McGuire has employed a Zipit Wireless Messenger as a weather station
>controller and 802.11b/g link for remote data acquisition for years:
>
>http://www.paonia.com/~kenm/Pix/imag...r/pict1442.jpg
>
>I ported 1-Wire code to this device to support a variety of sensors
>(temp, humidity, etc.), and even the old Dallas 1-Wire weather station
>could be interfaced to this machine.
>
>One gains the facility of local data caching, data verification and
>error checking, arbitrary control of sensors and equipment and
>flexibility in programming by using a general purpose controller
>and wireless LAN. The 'Zipit' is tiny and a power miser - about the
>size of a deck of playing cards.
>
>Michael
Thanks especially if the 'engineering' doesn't get too complex.
fundamentalism, fundamentally wrong.
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