Re: Web Enabled Time/Temp/Humidity and I/O Controller

["Robert Green" <robert_green1963@xxxxxxxxx>]

"Jim Hewitt" <jim.hewitt@xxxxxxxxxxxxxxx> wrote in message
news:hhtvir$cj3$1@xxxxxxxxxxxxxxxxxxxxxx

<stuff snipped>

> > Well, I'll let you know a) the Honeywell sensors even work (they came
from
> > a
> > guy in Canada, not a big electronics house.  They were half price, which
> > means only one of them probably works, b) if the two unit's readings
agree
> > with each other and c) if they agree with any of the other humidity
> > sensors
> > in the house (none of which agree exactly with each other, but are
mostly
> > within 10% of each other.  Mostly).
>
> Well, I got one for Christmas - from my wife!  So now I don't have to
think
> up projects to convince her - but I'm still thinkig up things to do.
>
> Any progress reports possbily available elsehwere?
>
> Jim

I wish I did.  I've run into one of those stretches where things seem to be
breaking down faster than I can fix them.  The incredibly, continuous, way
below zero weather we've been have has caused some pretty interesting
failures. Haven't even tested the dang humidistat or temp sensors to ensure
they work correctly.

I should probably look up the old threads concerning back-stabbed outlets
and hard-of-hearing smoke alarms and add some new information.  Had a
backstabber get so hot, it began melting wires.  The hard of hearing smoke
alarm apparently goes off for no particular reason and at the oddest hours
of the day so my elderly friend has yanked the batteries.  Not the outcome I
want.

But all the pieces of the web controller are in place now - got a
small Ethernet switch and some old laptops with network connection to create
a "sandbox" to play with the unit - the final pieces have arrived today.  I
found some 8.4VDC/0.6A switching power supplies to power the board.  Didn't
want to use the old non-switching adapters I had lying around because I
didn't have two match ones and I couldn't bring myself to cut a perfectly
good, strained-relief plug from one of my junk bin units.

These are Canon brand units that actually screw together so they might even
be repairable or filterable if they turn out to be too noisy, electrically.

http://www.allelectronics.com/make-a-store/item/PS-846/8.4-VDC-0.6A-SWITCHING-POWER-SUPPLY/-/1.html

I just checked these out on the bench and they are voltage regulated to
within .02 of a volt.  I found that they are very useful for running 80mm PC
case fans at whisper quiet level, and I have begun mounting these to various
TV's and amplifiers.  I thought there was something wrong with them at
first.  I plugged them in after stripping and tinning the leads and then
went to test the polarity so I could mark the positive lead red.  Well, my
electronics bench bottle of red nail polish had dried out, so I put some red
heat shrink on the positive lead.  Just because reversed polarity can kill
things, I checked one more time with an bicolor LED and resistor that I use
to test polarity and it glowed for a second or two and then went out.  Put
the voltmeter on it again, and it showed exactly 8.40VDC and then went
"hunting."  Turns out I had accidentally unplugged the power supply and I
was running off voltage stored in the caps.

I found another use for these PS's.  The IR thermometer I got for Christmas
(great toy, under $20 from Ebay, hundreds of uses - even SWMBO has found
uses for it.  Any, the thermometer was showing much higher temperatures than
I thought on everything from LCD TV's to amps.  (Sony appears to synchronize
their warranties with how long their gear will last without aux. cooling.)

I had a big Sony amp that would always trigger the thermal protector after
an hour or so of Pink Floyd, but since I added an 80mm fan running at 9V
(higher, actually because that PS is not regulated) it hasn't shut down
once.  Now the speakers are the first to pop a breaker, but I don't think
cooling will help them as much.  (-:  So anyway, I'm going to order some
more because they spin the fans fast enough to move significant air but
slowly enough so that they can hardly be heard.  Now you know why I am not
yet on the web controller project.  I'm easily sidetracked!  But I think I
can finally get a test unit rolling tonight.

Got a bunch of 6 & 9VDC DPDT mini relays (not sure which will work better),
some diodes to prevent the relays coils from spiking, some quick disconnects
and other miscellany because I like to be able to switch out things like the
main board without having to unscrew wires.

http://www.allelectronics.com/make-a-store/item/PCON-52/5-POLE-PLUG-IN-SCREW-CONNECTOR/1.html

I also have buckets of IDE hard drive cables because I do a lot of PC repair
and that's a commodity that seems to grow and grow in the junk bin.  Not
sure how I want to connect the sensor wires.  I might use the tons of
printer and serial cables I have lying around or I might get a
"daughterboard" for the controller that's got a 40 pin header to use ribbon
cables.  Either way, I'm designing the unit so it's "snap out-able" so if
anything goes wrong, replacement's a snap. (-:

I wish I could give you an update on the board and all the things I have
planned, but spare time seems to have completely disappeared since I
retired.  I'm still trying to figure out how that happened - it seems to
violate some sort of law of physics.  That's more than you ever wanted to
know, I'm sure.

(-:

Soon, very soon.

--
Bobby G.