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[bkenobi]

It looks like I have 3 options to consider.  I don't know which way to go and the investment (both in $$ and time waiting for shipments) is causing pause.

• Oregon Scientific I600
• Arduino
• WebControl

Oregon Scientific I600 - Looks like the USB controller will be able to read at least 3 thermo/hygrometers.  It may be able to read up to 10 devices, but I'm not sure and don't really need to do it anyway.  The up side is it's already wireless and should allow for control via whatever language I want.  The down side is that I would have to keep the software running all the time to keep the data recording as well as a separate program to monitor that data and send commands.  I think I can get up and running with this for $60USD+shipping or less.  Another thing to consider is that I would need to have an X10 device on each of the fans.

Arduino - Fairly cheap, but I'd probably need 2 (1 for each attic).  The programming would allow this to run on its own and would not require a computer to run.  I would need to get a few sensors and a couple relay boards from the looks of it.  Alternately, I could send X10 commands if I were to connect it to a FireCracker or one of the RJ11 connection X10 devices.  How do I program an Arduino though?

WebControl w/ X10 enabled firmware - Looks like the PLC commands are a bit basic compared to the Arduino.  I think this option is basically the same as the Arduino but harder to write code for.  On the up side, programming is as simple as logging on to the web server and pasting the code into the window.  This one even has a guide on how to modify a FireCracker to work to send commands.  On the up side, just like the Arduino, the controller can be programmed and installed in the attic without needing a PC connection.  With the WebControl, I could potentially connect it to the network and monitor as well...if I wanted.  Also, if connected to the network, I could send email notification for whatever reason (humidity has been high for a while, temperature is WAY too hot may be a fire, etc).

http://www.cainetworks.com/products/webcontrol/WebControlX10.pdf
http://www.redhillnetworks.com/manuals/webcontrol/WebControlPLCUserGuide3-01-06.pdf

Can anyone comment on any of my unanswered questions?

[systemdm]

Noam,

You may want one of these for breadboarding.  Thinking about ordering one myself.

http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_2151259_-1

[bkenobi]

Looks like a nice way to get all the components at once.  Obviously, the primary part of importance is the ATmega328P chip.  For now, I think I'm going to get a full sized Arduino Uno or Duemilanove 2009.  Looks like I can get either one for ~$20USD shipped.  If I remember correctly, Jameco is a bit steep for shipping on small orders.  The only thing that's keeping me from ordering right now is not knowing if there is a good reason to make sure I get an official Arduino or a clone.  The price isn't much different, but I can't see what the difference is at all.

I'm thinking I'll order a couple sample thermal sensors from Maxim-IC to play with before I step up to the DHT11/22.  I'll also be looking at getting some kind of relay setup to actually control the fans since it's both cheaper and more reliable than using X10 (especially since they aren't already set up that way).

Does anyone have any idea if the accuracy of the DHT11 is really that bad (+-2C and +-5%RH)?  If that's true, then I'll have no choice but to go with the DHT22.  If they aren't that precise, but they are accurate from one sensor to another, I'd probably be able to use the DHT11.  I'm looking at finding delta temperature and humidity from inside and outside the attic.  If they are accurate from one to the next, the delta would be consistent even if they weren't precisely reporting the correct humidity.  Temperature-wise, I could always just use the Maxim-IC temperature sensors which are pretty accurate.

FWIW, I'm thinking that I'll get one Arduino for testing and, once I get things working correctly, I'll get one or two more for the actual installation(s).  I'm thinking it would be much easier to install one at each fan location rather than trying to run wires from one side of the attic to the other (since they aren't connected and there's no easy passage).

[systemdm]

bkenobi,

Where are you seeing these for $20?  I found the Duemilanove for $27.00 on Amazon.

Thanks,
systemdm

[bkenobi]

I've been checking ebay.  Most of the cheaper prices are from Hong Kong.

[bkenobi]

I just ordered an Arduino UNO R1 from Hong Kong for $18.30 shipped.  The primary down side is that it will take weeks to get state side.

Your item(s) should arrive between Jan 25 - Feb 07, 2012.

DOH!  I'll have to find something else to do in the mean time I guess... 

[Noam]

Noam,

You may want one of these for breadboarding.  Thinking about ordering one myself.

http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_2151259_-1

I can't get the page to load. What is it?

[bkenobi]

It loaded for me fine earlier today.  Looks like the site is broken right now cause I can't even load the main page.

[Brian H]

May have been a server problem. The link is working again.

[bkenobi]

One thing to note about that Jameco kit is that it may not have any Arduiono boot loader flashed to it.  If not, then you will need to have some way to flash the chip.  That's not difficult, but it's something extra to keep in mind.  There may be other kits that include a pre-flashed chip.

[Noam]

Is that just a kit of parts to build your own Arduino on a breadboard?
Since I'm still pretty new to this, I'd prefer to use a pre-build Arduino, one that I can just slap a "standard" prototyping shield onto when I'm ready to move my circuit from the breadboard to "real life" use.

[bkenobi]

Yes, that's a kit that doesn't appear to include any kind of perf board or anything.  I just found that Fry's sells Arduinos for a comparable price to the US ebayers (~$30).  The appear to even have several versions available.  These are not the official Arduino brand, but they should work fine.  If I had known they were available locally for just a bit more, I probably would have gone that route since I'm now sitting here twiddling my thumbs waiting for the slow boat from China...literally!

In the mean time, I've been doing some reading on the Arduino and weather stuff and have come to find several projects that capture the remote sensor data being transmitted over 433Mhz.  There are radios that are ~$10USD that can be hooked up that will allow for the prebuilt libraries to capture the data and display it to some compiled applications even!

http://www.practicalarduino.com/projects/weather-station-receiver

[Noam]

Yes, that's a kit that doesn't appear to include any kind of perf board or anything.  I just found that Fry's sells Arduinos for a comparable price to the US ebayers (~$30).  The appear to even have several versions available.  These are not the official Arduino brand, but they should work fine.  If I had known they were available locally for just a bit more, I probably would have gone that route since I'm now sitting here twiddling my thumbs waiting for the slow boat from China...literally!

In the mean time, I've been doing some reading on the Arduino and weather stuff and have come to find several projects that capture the remote sensor data being transmitted over 433Mhz.  There are radios that are ~$10USD that can be hooked up that will allow for the prebuilt libraries to capture the data and display it to some compiled applications even!

http://www.practicalarduino.com/projects/weather-station-receiver

Around here, both RadioShack and MicroCenter carry Arduinos now.

[bkenobi]

My Radioshack's don't carry them normally, but they do offer a "ship to store for free" option.  The price is starting to get too expensive especially with ~10% tax, but it's a nice option in a pinch especially since they carry the current revisions (UNO Rev3).  The ones at Fry's are all knock offs (OSEPP brand).

Does anyone think using X10 for the actual fan control is a bad idea?  I don't think I've really had a problem with PLC signals for months (none since I installed the phase coupler).  The RF is a different story, but if I used a firecracker, it would be in the attic right next to the CM15A antenna.

One other thing about the DHT11/22/etc.  How would I weather proof one of these?  I was thinking that if I used these, I'd try to stuff it in an upside down pill bottle and cover the bottom with mesh of some kind (to keep bugs out).  I'm thinking it would be easiest to stick it out the fan louvers and just hang it at the end of the house or else re-purpose an unused hole for the old satellite dish coax.

[Noam]

One other thing about the DHT11/22/etc.  How would I weather proof one of these?  I was thinking that if I used these, I'd try to stuff it in an upside down pill bottle and cover the bottom with mesh of some kind (to keep bugs out).  I'm thinking it would be easiest to stick it out the fan louvers and just hang it at the end of the house or else re-purpose an unused hole for the old satellite dish coax.

I did almost the same thing. I took a prescription bottle, and drilled a hole in the cap. I then drilled about 10 more holes around the sides of the bottle, to allow air to flow in and out. I fed the sensor (I'm using a Dallas OneWire DS18S20) through the hole in the cap, and put a foam spacer around it, to try and keep it centered in the bottle. That was fed out through a fresh-air vent, which has a screened "cage" outside. the bottle is sitting in the cage.

It worked fine overnight, but I noticed a rapid rise in temperature today at around 10 AM. the sensor I stuck in between the window and the storm window on that same wall also showed a dramatic temperature increase at that time. I think that's when the sun moved out of the shadow of the shed, and was hitting that wall. It is a brick exterior wall, and I know they radiate heat for a long time.

My eventual goal is to take an outdoor electrical box, and mount it to the wall. I would drill a serial of holes along the sides and bottom, and line them with some bug screen I had leftover. Then, it is "only" a matter of cleaning up the rest of the mess.