Re: RFID for HA

[Marc F Hult <MFHult@xxxxxxxxxxxxxxxxxxxxx>]

On Mon, 17 Apr 2006 13:12:36 -0400, "E. Lee Dickinson"
<lee@xxxxxxxxxxxxxxxxxxxxx> wrote in message
<e20iak$sed$1@xxxxxxxxxxxxxxxxx>:

>
>"Dan Lanciani" <ddl@danlan.*com> wrote in message
>news:1331814@xxxxxxxxxxxxxxxxxxxxxx
>> In article <e0ves8$53g$1@xxxxxxxxxxxxxxxxx>, lee@xxxxxxxxxxxxxxxxxxxxx
(E.
>> Lee Dickinson) writes:
>>
>> | This strikes me as a terrific idea. The whole reason I'm interested in
>> RFID
>> | is to know if my cars are in the driveway. If both are gone,
temperature
>> | adjusts, doors lock, roomba vacuums... etc.
>
><snip snip>
>
>> It is critical for the car-based device to boot up and start responding
>> to queries before the car gets out of range when starting/leaving.  Even
>> many DOS-based laptops waste a lot of time in the POST, making them
>> useless.
>
>
>Don,
>
>Thanks for your response. I've been mulling this over for a few weeks now,
>trying to figure how to slim this down even more. I was thinking of
>something as simple as a USB access point in the car, with a script to
>detect when its mac address showed up on the network.  Problem there is one
>you've already identified:  You need some sort of uptime to tell the
>difference between an arriving car and a starting car.
>
>This is very interesting to me, and I'll continue to persue it and let you
>all know what I come up with.
>
>Anyone else have any ideas?  Wifi instead of RFID.. the $500 cost savings
>have me drooling.


The price of WIFI routers has dropped below $50.

Linksys open sourced the WRT54G Linux firmware in July 2003.

http://www.linuxjournal.com/article/7322
http://www.wi-fiplanet.com/tutorials/article.php/3562391

They boot in a few seconds.

All one would actually need is a 555 IC (or other timer) that would wait x
minutes to power up any detectable characteristic of the router to
distinguish between coming and going.

Teaching the Linksys to do other things would be the gravy.

... Marc
Marc_F_Hult
www.ECONtrol.org