Anyone need a project? [SNMP temp sensor]

[David Lesher]

I hang out with a bunch of network admins [they let me post to their
list if I don't talk BGP...] and one (and likely most...) are seeking
a environmental sensor:

a) Reasonably small. This probably wouldn't be rack mounted; it'd
be wall mounted, desk mounted, ceiling mounted, etc.

b) Powered by PoE.

c) Is SNMPable over Ethernet. NOT RS232 or serial, or anything
archaic like that. Not MODBUS. It's 2004, people. [Hey, I add, what
about Fallon PhoneNet....]

d) Provides Temperature and Humidity measurement.

e) Has 4 or so input contact sensors (connections to AC units, etc.)

f) Has 4 or so output contact sensors.

I added:

g) cheap, so as to encourage quantity deployment.

to the requirement set.


Now, absolutely accuracy is not a big issue; they just want to know when
the AC has quit, or the humidity is WAY too low, etc.

So what do the collective geniuses of s.e.d think is the best solution?

 

[Genome]

I hang out with a bunch of network admins [they let me post to their
list if I don't talk BGP...] and one (and likely most...) are seeking
a environmental sensor:

They just want to know when the AC has quit, or the humidity is WAY too

low.

The lights go out.

The sandwiches curl up at the edges.

DNA

Next week, Advanced orgasms for lesbiens.

 

[Richard H.]

I hang out with a bunch of network admins [they let
me post to their list if I don't talk BGP...] and
one (and likely most...) are seeking a
environmental sensor:

Except for a) small, b) PoE, and g) cheap, there are already such
products on the market for monitoring the power, door contacts, temp,
humidity, etc. in data centers. Start with the UPS manufacturers.

There are several small/cheap Ethernet project sites out there, but none
are doing PoE yet that I've seen, so you'd need to roll that in. Here's
a popular one that'd need to be trimmed back to reduce cost:
http://www.ethernut.de/en/hrz/index.html

Linear has been doing PoE for years now, heavily in Cisco's products:
http://www.linear.com/pc/viewCategory.do?navId=H0,C1,C1003,C1006,C1125
And an article on PoE:
http://www.elecdesign.com/Articles/Index.cfm?ArticleID=5945

On the super cheap side, start with something as a derivative of
http://www.picoweb.net - add PoE, a handful of input and output drivers
for the contacts, and a one-wire sensor for temp and humidity. Or maybe
something like the project boards here: http://www.edtp.com

More expensive, more compact, and closer to turnkey, products like the
XPort and DigiME are pretty slick but don't offer PoE last time I
looked.
http://www.lantronix.com/products/eds/xport/index.html
http://www.digi.com/products/embeddeddeviceservers/digiconnectme.jsp

comp.arch.embedded would be another place to ask around.

Have fun!
Richard