Cheap / Simple Humidity or Temperature to ISY ?

[telljcl]

I've got thermostats that relay this info to my ISY, but they aren't cheap.

 

I've also got an ELK which has modules available that can do temperature (don't have any), but they aren't cheap either.

 

Prefer a hard-wired solution (I use many ELK alarm sensors for automation tasks because they are reliable) but maybe

there is a z-wave device that is cheap and easy to integrate into ISY? (I have zwave module but no zwave stuff).

 

Thanks for any insight.

 

[Teken]

I've got thermostats that relay this info to my ISY, but they aren't cheap.

 

I've also got an ELK which has modules available that can do temperature (don't have any), but they aren't cheap either.

 

Prefer a hard-wired solution (I use many ELK alarm sensors for automation tasks because they are reliable) but maybe

there is a z-wave device that is cheap and easy to integrate into ISY? (I have zwave module but no zwave stuff).

 

Thanks for any insight.

 

Lots of cheap sensors but none of them will offer very low / high accurate temperature or humidity. If you're so inclined I can offer you a few resources that will be worth the long term investment.

[telljcl]

Thanks for the info.

 

Absolute accuracy may not be that important in this case as long as the variability of said accuracy is minimal.

 

Also, I'm really (in this case) just wanting to read if the humidity is high enough that a shower exhaust fan needs to come on, then go off when the humidity is down again.

 

What are the resources you recommend?

 

Thanks

[Teken]

Thanks for the info.

 

Absolute accuracy may not be that important in this case as long as the variability of said accuracy is minimal.

 

Also, I'm really (in this case) just wanting to read if the humidity is high enough that a shower exhaust fan needs to come on, then go off when the humidity is down again.

 

What are the resources you recommend?

 

Thanks

 

Since you indicated going the route of Z-Wave might be an option you could consider this device: http://aeotec.com/z-wave-sensor

 

As you also indicated so long as the reading is (repeatable) never mind accurate this would fit into your environment quite nicely. If you're looking for something that is wired and offers true accuracy and over the long run will not cost you more money in terms of batteries etc.

 

You can go the route of a 1 Wire system which can be supported by a Autelis Bridge, Raspberry Pi (RPi-2), or Web Control board. All of these are hard wired solutions and offer reliable, consistent, and long term use. Keep in mind if fishing wire is not in the agenda then a wireless solution is the best choice.

 

But the out of pocket expense will be more initially, and long term.

 

If you need more insight about the Autelis Bridge you can find it here: http://www.autelis.com

 

This is a guide I created to help those track their efforts with a free hosted site (SEG) so you could see the historic data and act upon it: http://forum.universal-devices.com/topic/16095-autelis-bridge-pushing-data-to-smart-energy-groups-seg-guide/

 

The following link goes to a massively long *Install Thread* which I use to track my efforts in all things related to the home automation, security, and energy solutions with in my home: http://www.brultech.com/community/viewtopic.php?f=2&t=929&start=80

[fryfrog]

How about one of the new Aeotec Multi Sensors? You get humidity and temperature along with a bunch of other useful information. They're not that expensive and they can be hard powered via USB (but they're still zwave of course). I got 2 to test with and like them so far, another 10 arrived a few days ago. Can't wait to start putting them up!

[Teken]

Since you indicated going the route of Z-Wave might be an option you could consider this device: http://aeotec.com/z-wave-sensor

 

 

How about one of the new Aeotec Multi Sensors? You get humidity and temperature along with a bunch of other useful information.

 

Indicated above . . .

[fryfrog]

Indicated above . . .

 

Ha

[telljcl]

Those Aeotec multisensors look interesting.  Can't seem to find the recessed mounting option for them anywhere at the moment.  Appears they are working reasonably well for people.  Might have to try some out (maybe for other uses as well).  Any other suggestions?  Remember I can use the ELK also, so any sensors / modules for that could be used.

 

Thanks!

[larryllix]

I use the WebControl board as a cheap option. I would use it again for certain situations as I am familiar with it and it is easy to interface to the ISY. I use it to stuff in/out high/low for the day temps, humidity, wind speed and wind gust speeds into ISY variables.

 

- I had no success with the 1-wire  combo humidty/temperature sensor (24B38? Autelis doesn't support either, RPi does) for sheepwalk electronics. Support drivers have since been discontinued in newer versions of firmware.

 

- it has a direct humidity sensor input that appears to work well directly connected.

 

- it supports 8 x 1wire DS1820, DS18B20 etc.. temperature sensors  on one 1Wire input very well, analogue &TTL inputs and TTL outputs

 

- runs on 6-12vdc PS

 

- it has  hardware counter input good to 2 MHz.

 

- it can do direct email on command and stuff 8 different variables/programs/device controls directly into ISY via Ethernet

 

- supposed to control X10 devices but why would I want that with an ISY?

 

- newer modules have been heat tested to 70-80 degrees C  after some complaints about heat in boxes out in the sun.

 

-watchdog built in will reboot if failure detected.

 

- UTC based real-time clock with access, for time slice program execution or integration of event counts over time.

 

Note: These DS18B20 sensors you can buy on eBay for $1.99 are 0.1 degree resolution and 0.5 degree rated accuracy. With a more accurate standard I am sure you could calibrate them individually by tweaking the curve in software. I believe these sensors are stable to maintain consistency. after a burn-in period.

 

EDIT: corrected  IC names.

[larryllix]

How about one of the new Aeotec Multi Sensors? You get humidity and temperature along with a bunch of other useful information. They're not that expensive and they can be hard powered via USB (but they're still zwave of course). I got 2 to test with and like them so far, another 10 arrived a few days ago. Can't wait to start putting them up!

Interesting unit!

 

It seems there has been many different versions and they have changed their battery requirements a few times now.

 

The Aeotec site shows the latest version taking two CR123A batteries. These are a 2/3 AA size 3v lithium battery. My old camera used those and something to beware of. They did cost over $15 a piece, years ago,  making a battery change about $30 per year or sooner.

 

I also found some bitching about the batteries dying while trying to setup the unit. I couldn't determine if batteries  came with the units or not.  YMMV.

[fryfrog]

Interesting unit!

 

It seems there has been many different versions and they have changed their battery requirements a few times now.

 

The Aeotec site shows the latest version taking two CR123A batteries. These are a 2/3 AA size 3v lithium battery. My old camera used those and something to beware of. They did cost over $15 a piece, years ago,  making a battery change about $30 per year or sooner.

 

I also found some bitching about the batteries dying while trying to setup the unit. I couldn't determine if batteries  came with the units or not.  YMMV.

 

Now-a-days they're $1.5-$3 on Amazon, but Aeotec claims they'll last 2 years. The first pair I ordered came with batteries, the next 10 didn't. I got the first 2 from a pre-order at http://www.thesmartesthouse.com/where they say they come with batteries. I got the next 10 from the same shop, but their Amazon store. So be sure you order from their own site if you want batteries.

[telljcl]

Larry, 

 

Interesting stuff on webcontrol board and sensors. seems relatively simple.

 

I would assume you could locate temp / humidity sensors at the end of a wire (20-30 feet maybe?) from webcontrol board or do they need to be attached directly to the board?  I'd like to use one board and attach several sensors a short distance from it.

 

Couldnt find the "2420 or 24b20" sensors you mention on ebay?

 

Thanks!

[arw01]

So the webcontrol board reboot issues have been resolved?  What's the current url for buying them, would eventually like some humidity sensors and I've had enough issues with Pi's that I may not want to complicate my life with another one or 5..

[Teken]

The problem you're going to run into with some of these products is the lack of real world distance. So this needs to be kept in mind and some of the products also don't support humidity sensors very well as Larry indicated for the Web Control Board.

 

For reference sake here is what incredible data you can obtain and have all charted, graphed, and displayed live.

 

 

[larryllix]

Larry, 

 

Interesting stuff on webcontrol board and sensors. seems relatively simple.

 

I would assume you could locate temp / humidity sensors at the end of a wire (20-30 feet maybe?) from webcontrol board or do they need to be attached directly to the board?  I'd like to use one board and attach several sensors a short distance from it.

 

Couldnt find the "2420 or 24b20" sensors you mention on ebay?

 

Thanks!

Need to look harder. Darn! I used the wrong prefixes....fixed  They are very popular, everywhere and frequently sold in groups of 5, 10 or 100 pieces.

 

http://www.ebay.ca/itm/1pcs-DS18B20-Waterproof-Sensor-Digital-thermometer-Thermal-Probe-ds18b20-sensor-/131559792384?pt=LH_DefaultDomain_0&hash=item1ea1931f00

 

 

The Webcontrol rebooting was resolved by not attempting to support the DS2438 humidity sensor and finally increasing the watchdog time.  It seems the board's limited memory space being shared was causing too much delay between 1wire and Ethernet comms and the board watchdog would assume a crash and reboot.

 

This humidity sensor was never supported by Webcontrol or Autelis (never implemented it). The interface is very difficult to interface on the same 1 wire port with the other more common probes. IIRC, it used a faster bit rate and has many more registers internally. RPi does it, though.

 

Humidity IC  can be direct connected to the board and not via 1Wire. I wouldn't want to extend leads more than about 6-10 feet from the board.

 

My temperature probes on 1 wire would be fine for less than 15-20'. The interface is very raw, right into the CPU pins, without filtering etc. Others use long cables with the 1wire successfully. I had my 1wire humidity sensor confusing the issue and haven't got back to lengthening my just temp probe cables yet.

 

After reading more on 1wire slew rates, and scoping the lines, I figure I can make this reliable with a few simple parts and I was doing it wrong. The WebControl switches the line too fast, and causes echoes, while the well designed probes seem to have a slower slew rate and do not cause overshoot in signals.

[Teken]

Need to look harder They are very popular ad everywhere and frequently sold in groups of 5, 10 or 100 pieces.

 

http://www.ebay.ca/itm/1pcs-DS18B20-Waterproof-Sensor-Digital-thermometer-Thermal-Probe-ds18b20-sensor-/131559792384?pt=LH_DefaultDomain_0&hash=item1ea1931f00

 

I believe he went with your 2420, there are no 1 Wire sensors that start with that value and the most common are the ones you referenced which are DS18B20. 

[larryllix]

I believe he went with your 2420, there are no 1 Wire sensors that start with that value and the most common are the ones you referenced which are DS18B20. 

Thanks Teken. Yeah I confused the DS1820 with the DS2438 part numbers.

 

Apologies for the confusion.

[telljcl]

So let me see if I have this straight - the Webcontrol board using cheap temperature sensors IS reliable and fairly easy (no reboot issues, programming work-arounds etc...) to implement with ISY, but the humidity sensors (what part #?) do NOT work reliably at this time?  And these (that apparently aren't reliable) can only be soldered to about 10' of wire max away from the board?  Is the humidity accurate if you solder / attach the sensor directly to the board or is it that the board and sensor combo do not work together (without modification / fancy programming / special circumstances etc...) ?

 

Thanks and sorry if I'm slow to get this

[Teken]

I can't speak to how far the RPi and Web Control Boards go in terms of over all feet. But lots of forum threads indicate most of them don't go past 20-30 feet very well and that's only with a 1-8 sensors in place!

 

I have 32 sensors exceeding one mile in my network and thus far haven't seen any issues at all. Besides a couple failed 1 wire sensors which I can't really cry about since they only cost me $1.25 a piece. Ultimately when all of the sensors arrive from China my 1 Wire network will support 72 sensors in the grid.

 

Good luck . . . 

[io_guy]

The WC uses the GPIO bus to big-bang (software) its one-wire.  This is why the distance is poor.

 

Grab a hardware one-wire chip for the Rasp Pi and you'll have no issues.  It also supports unlimited temp and humidity sensors.

[larryllix]

Each 1wire probe/IC takes a custom designed interface to use that probe. There are no generic drivers to accommodate a line of them.

 

The DS2438 battery management chip is used  because it has a temperature sensor built in and an A/D converter that allows the use of an analogue humidity sensor's output. The DS2438 also talks 1wire to controllers. The DS2438 battery management chip is used in the SWE3 combo sensor board and offers temperature and humidity in one connection.  Apparently the DS2438 chip uses a quite different interface style from the common DS1820 temperature probes people are using mostly so gives firmware writers a problem.

CAI with their WebControl 8 board attempted to create a driver for the DS2438 chip but had many problems with it. They since discontinued support for the DS2438 chip on their 1wire port.  Autelis (that Teken has) never supported the DS2438 chip AFAIK.  RPi uses an adapter and can support the DS2438 chip. I have tried it and it works. 

 

WebControl 8 and Autelis both use a bit-banger interface (mostly software) and multitasking, timing critical, interfaces can be a problem depending on hardware timers etc. available to support the software interface. Rpi is mostly done in hardware and tends to be more reliable and more costly with interface cards and custom enclosures required.

 

I explained the reboot problem previously and let me add that I was monitoring the WebControl stuffing date and time into my ISY every 8 and 10 seconds and not allowing any misses. Once I dropped the 1wire humidity sensor, CAI loosened their watchdog timing, and I loosened my watching noose, the problem basically went away. Many others never had a problem, not watching so closely, and not trying to add weird sensors using long cables.

 

CAI WebControl board has a discreet set of 3 terminals to direct connect a humidity sensor. As I stated before I would not want to increase leads by more than about 5-6 feet due to noise pickup on sensitive lines. Untested. Shielding and other techniques would be in order for longer lengths.

 

CAI has available a WebControl 32 board that implements 1wire in hardware also. No experience but they both use an easy to write PLC language with limited memory space but usually workable for any controller application.  The Autelis may be a good compromise if not too many customisations are required at that end of your system. Teken would have to tell you about any logic that Autelis can do. If you are an adept programmer with Linux and Python experience, the RPi offers all the options for multiple applications but the learning curve is very steep and help can be very hard to find that applies to your 1 of 10,000 different distros, hardware, python versions and other options. I found most information didn't apply.

 

All options are going to run you $120-200 or more to get up and running.  RPi will require a spare keyboard and newer monitor with HDMI inputs to get going.

 

You have to pick the complexity of setup vs flexibility as a tradeoff.

[Teken]

Just to clarify the Autelis Bridge does not officially support the DS2438 chipset. But Autelis has updated the firmware to allow it to be used and it has been reported by several users that it operates just fine.

 

Once the Canadian dollar is out of the toilet I plan on purchasing 4-6 of the humidity sensors for my home. My ultimate goal is to get as much *accurate* and local data from my sensing grid to help automate the homes active / passive cooling systems. Having more conditional logic on hand will help fine tune many programs and how the Insteon network operates.

 

I've personally pushed the envelope of energy conservation to the limits within my home. The next step for me is complete and total environmental control that has enough real world logic and feed back. I haven't had one moment of regret going the route of 1 wire versus some kind of battery operated device.

 

The reality is unless the battery operated device is purpose built and exceeds $100.00 you will not see any true accuracy for humidity / temperature.

 

As others stated some just need a general idea whereas for me reliability, accuracy, and long term costs was the goal.

[Scott847]

...

All options are going to run you $120-200 or more to get up and running.  RPi will require a spare keyboard and newer monitor with HDMI inputs to get going.

...

 

The cost of a Raspberry Pi 2 to do temperature and humidity monitoring/logging is currently $79.

 

An external monitor, keyboard and mouse aren't necessary. You can write the Raspbian Linux image to the microSD card and connect to it using PuTTY or some other SSH terminal software. The first time the Pi boots it will be "raspberry pi" on your network and many routers will allow you to connect using that host name (or you can log into your router to see what IP address was set by DHCP). After logging in the initial setup command is: sudo raspi-config.

 

Component costs on Amazon are: $70 CanaKit Pi 2 Starter Kit (Pi2, 8 GB MicroSD, WiFi Adapter, Power Supply, Case) + $9 for a DHT22 temp/hum sensor (SMAKN DHT22 AM2302). This doesn't include the breadboard, wires and a pull-up resistor shown in the photo.

 

This is a photo of a Raspberry Pi I set up this afternoon to log to Smart Energy Groups. I'm using an Edimax WiFi adapter here but so far I've found it interchangeable with the WiFi adapter included in the CanaKit Starter Kit (except this one doesn't stick out as much).

 

 

...

The reality is unless the battery operated device is purpose built and exceeds $100.00 you will not see any true accuracy for humidity / temperature.

...

 

I've been testing the emonTH, which is a wireless, battery-powered remote temperature sensor. It can use DHT22 (temperature and humidity) and/or DS18B20 (temperature only) sensors.

 

The DHT22 specs are RH range 0-100%, +/- 2% (max 5%), temperature -40 to 80 Celsius, +/- 0.5.

 

Current cost for an emonTH with a DHT22 sensor and case is 32.30 GBP ($50 USD). The RFM69Pi device on the Raspberry Pi side can communicate with multiple emonTH's and costs 15.50 GBP ($24 USD).

 

More about this at http://openenergymonitor.org/emon/modules/emonTH

 

Getting back to the OP question, so far I've found the Aeotec MultiSensor 6 that Teken had mentioned is pretty good if you calibrate the temperature and humidity readings using its Z-Wave configuration parameters.

[io_guy]

 

If you are an adept programmer with Linux and Python experience, the RPi offers all the options for multiple applications but the learning curve is very steep and help can be very hard to find that applies to your 1 of 10,000 different distros, hardware, python versions and other options. I found most information didn't apply.

 

All options are going to run you $120-200 or more to get up and running.  RPi will require a spare keyboard and newer monitor with HDMI inputs to get going.

 

 

Not as difficult as you mention here.

 

- Headless - no HDMI, KB or Mouse required.  I've never connected a monitor to a Pi.

- Install Wheezy per guide in forum.

- Configure OWFS and one-wire board per Sheepwalk's info.

- Install OWLInk.

- Done, no programming or Phython required.

[telljcl]

Lots of options and I welcome all the advice.  I'm looking to keep it pretty simple (no new programming if I can avoid it) but I did order an Aeotec and a Webcontrol board with some temp sensors.  I plan on following the guide posted earlier to get that thing working to monitor 6 or 8 diff temps.  What is the preferred wire for extending temp sensors?  Shielded?  It's 3 conductor so should each conductor have its own shield or will UTP wire work OK?

 

Thanks!