On Thu, May 14, 2009 at 14:33, Jan Kandziora <jjj@...> wrote:
> Am Donnerstag, 14. Mai 2009 schrieb Rob Fugina:
>> I need to get some 1-wire weather instruments mounted away from my
>> house, on a post about 75 ft away. This worries me because of how the
>> system basically becomes an antenna. Nearby lightning strikes would
>> wreak havok back at the bus master.
> A lightning striking a pole only ~25m away would shift earth level very much
> and damage most of your computer equipment anyway. It makes no sense just to
> protect one input -- You'll have to protect all inputs, especially the mains.
> Where exactly do you live? A single house or an urban area? Are thunderstorms
> frequent? How dry is the soil at your area? These are important questions if
> you ask how to protect your equipment from lightning.
Ok, you're right, and I'm not really trying to protect myself from a
direct strike. But having a 75m antenna sticking out into my back
yard does seem to be asking for nearby lightning, or overhead
lightning, to induce significant current in that wire -- or am I
wrong? I live in the far suburbs -- very few trees, 1-acre lots,
houses 50m to 150m apart. The soil's pretty wet right now, and I
would say it never gets all that terribly dry.
In answer to Paul's suggestion, I hadn't really considered running a
full-on WiFi node on that pole, but I'm sure that's a possibility,
too. When I said "wireless" I was thinking of something at a much
lower level -- at the 1-wire level, in particular... But I've been
thinking about this more now, and I've got an NSLU2 hiding somewhere
in my house, and I have a pair of 10base-F transceivers that I got at
a hamfest a while back. Now if I could just power the NSLU2 and a
transceiver and bury some fiber, that'd 100 times more reliable than
wireless, and perfectly isolated. Now I wonder what it would take to