Low power one wire newbie

[StBarnabas]

 Hi all,
Much has been covered recently and I am reluctant to start a new topic, but it might be useful to gather more recent views.
Over the past year I have installed a 40 Tube Navitron solar water system, an Air source heat pump and Ground source heat pump. During 2009  am hoping to install a3KWp PV system and my next phase of underfloor heating complete hopefully with a wood burner and a back boiler that can be integrated with the GSHP system. Wind is for the future if I can ever purchase the land I need to get away from the turbulence surrounding StBC.

Some of this is well publicised on the forum. In parallel however  I have bee look into data logging systems and one-wire seems to be the way to go. It is difficult to know on this forum but I probably have more programming experience than most:
1976 started programming; 1978 first email address; 1981  on the internet (actually SERCNet [which later became part of JANET] at the time I managed node 42 - the Sheffield University connection) and have been programming etc. ever since.

On Kristen's advice I purchased the WeatherToys book- Have installed Java and NetBeans on my PC and have read up about 1-wire. I think it is definitely the way to go. This looks fine but it only seems to support a serial port and the thought of using my desktop PC (a lousy 170W) 24/7/365 does not fill me with enthusiasm. (My electricity usage is shameful enough already).

I aslo have amongst others an ASUS Eee-PC which is far more to my liking.


I suppose what I am asking is has anyone successfully used an ASUS  or a lower power technology with 1-wire? I would need of course a USB/1-wire card. I also like the thought of programming in Java or C so a solution which allows that wold be useful.

Sorry if this posting lacks novelty. But would appreciate ideas as some of you have some years experience with 1 wire and it will be very much appreciated
StB

[wyleu]

There is always this...



http://www.hobby-boards.com/catalog/product_info.php?cPath=23&products_id=1503

If your thinking linux and one-wire do check out http://www.owfs.net

I was at Sheffield 78-81 doing Electronic Engineering badly, and putting on bands only slightly better. Did a little bit of drum beating for a thing called Sohonet some considerable time ago. Watched some fairly early ATM cells do their stuff, ALL THE WAY DOWN TO PORTUGAL AND BACK!

[billt]

Yes, I've just moved me Homeseer system over to an MSI wind type netbook. Pretty much the same as the Intel Atom powered Asus netbooks. More than enough power to run XP and Homeseer and Homeseer is a much more demanding application than a simple 1-wire only logger. Only draws about 12W.

This is logging 1-wire temperatures with a TEMP-08 serial interface and a DS9490 USB i/f as well as various RF sensors.

When I've finished installing the log boiler & accumulator I will set up another Netbook purely for logging that.

[stephend]

Used netbooks off e-bay are hard to beat for low power consumption, price and usefullness (what with a built in screen and keyboard).  Other options are gumstix computers (http://www.gumstix.com/) and small form factor PCs like pico-itx: http://www.mini-itx.com/reviews/pico-itx/

[hiccup]

Hi

DS9490R USB host interface also available here

http://www.homechip.com/catalog/product_info.php?products_id=30

I'm using Barix Barionet for temperatures, it handles up to 50 1-wire temperature sensors - it does not do other 1-wire devices yet:



http://www.barix.com/Barionet/511/

It also talks modbus and they do a modbus node called X8 which can handle up to 8 1-wire temperature sensors. That allows me to distribute the sensors but interconnect the main areas with modbus rather than 1-wire. (The X8 also does analog input and digital in/out on its 8 ports.)

Not cheap but very low powered - although little internal memory for logging it is web and telnet enabled and can log anything via syslog.

Hope this is useful

Hic!

[Paulh_Boats]

StB,

The easiest start is the Hobby Boards USB interface that wyleu suggested.

Then download LogTemp and 1-Wire drivers (both free) and it will be reading temperatures within 10 minutes and plotting them on 3 graphs: day, week, month

Then use the FTP facility within LogTemp to upload its graphs/XML to your ISP home page.


LogTemp does just about all we need. By FTP-ing data to your ISP home page, HTML pages can be written to display the graphs or tabular data. The big advantage is that the whole world can see the performance of your system.....anytime.....anyplace....anywhere.... because there's a wonderful world we can share.

cheers
Paul

[kristen]

I too am using a DS9490R USB host interface and LogTemp (but I have all the WeatherToys and Java Development and Netbeans stuff installed too - albeit on-another-computer just-in-case)

Couple of links to some other posts I have made in case helpful:

Has links to LogTemp and various drivers & ancilliaries
My feature list review of LogTemp

[wookey]

Or of course you can use a Linuxed netbook and use http://sourceforge.net/docman/display_doc.php?docid=18012&group_id=85502 owfs or http://sourceforge.net/project/showfiles.php?group_id=85502&package_id=161992 temploggerd (or http://sourceforge.net/project/showfiles.php?group_id=145625 w1retap). All three support that USB interface (owfs supports serial and I2C too). Current kernels have device drivers built in so just plugging in that interface and some temp sensors will load the necessary drivers. (don't try to run the kernel drivers _and_ owfs low-level support - choose one or the other).

There is a very useful forum here:
http://www.cocoontech.com/index.php?showforum=41

[StBarnabas]

All
many thanks for all your help. I will get both a usb and serial interface and start by ordering a number of temperature sensors (DS18B20) if I order 25+ they are  £2.53 and 100+ £2.12 each from RS. I could see myself using 25 though possibly not 100. If anyone else is looking for sensors I can put in a bulk order. If you can let me know within the next few days. Link:

http://uk.rs-online.com/web/search/searchBrowseAction.html?method=searchProducts&searchTerm=DS18B20

Of course they may be cheaper elsewhere?

StB
 

[hiccup]

The usb interface is £12.26 from http://www.homechip.com/catalog/product_info.php?products_id=30 - they also do serial interfaces.

Hic!

[StBarnabas]

Thanks  Hic!

that's a good price. I have seen it for over twice that elsewhere! I have just ordered this and a serial interface.

Does anyone know a supplier which has a DS2405 in stock? Both RS and Farnell seem to be out of stock. These look as if they can with a little circuitry be used to count pulses from my electricity meter 1000 pulses per kWh and be used to connect to my anaemometer (curently sitting unused in my garage).

StB

[sunshinekid]

I started programming in dBase II.  Not because I started programming very early, just that I'm really old!  @10,10 say "Amount" picture "##.##" ah takes me back.  They don't write languages live that any more. Good.

Our woodburner installer convinced me 1-wire was the way to go and after checking it out I was impressed.  I know you can get nice interfaces to a 1-wire network like USB and serial interfaces, but being me I had to do it all myself.  I also had a PIC development kit and was looking for a project.

The 1-wire network can be driven directly from an I/O pin on a PIC chip so that's what I did.  I have around 40 feet of UTP cable and decided against parasite mode as it's a bit tricky and also decided to run the +5v up to cable as it may come in useful.  Once set up, the network is very reliable, even with the cable in close proximty to pumps etc.  I had to play with the pull-up resistor as I occasionally CRC errors around 80 degrees.  1K now works perfectly.  There are 8 sensors on the system currently.

So in the end I managed to build a small self-contaned unit with a single PIC chip, software RTC 1-wire interface and 1GB SD card.  The unit logs the temps every second (or more) to a CSV file on the SD card and I can import this into a spreadsheet and be an anorak for hours.

Most of the coding was OK apart from the 1-wire search routine which finds all the devices and almost broke my brain.  Works now though and I'm never going to touch it again!

Currently I'm playing with replacing the nasty pluggy inny SD card with some nice soldery inny flash memory and make it battery powered.  Lots to learn with all the clever shutdown and sleep features of the PIC chip, but all very interesting to me.  It would be good to run it from single CR2032 battery with a  year's life.  Fingers crossed.

On the 1-wire supply front.  Don't forget you can get small numbers of free samples from maxim-ic.com.

Best of luck with your proj.

Cheers

Steve

[StBarnabas]

Hi Steve

never used Dbase II (- though naturally I have heard of it) my early programming was in FORTRAN, APL, BCPL and of course various dialects of Basic. I started programming in Kernighan and Ritchie c in 1985.

Your use of a PIC with 1-wire is very interesting. This was going to be my first choice - started using P16F84's in 1997. I would be very interested in looking at your code. Do you program in assembler? What chip did you use?    I can see this project soaking up more of my time than intended!

StB

[hiccup]

From the Maxim site:

"The DS2405 is no longer available. The 1-Wire DS2413 with 2-CH GPIO functionality is recommended as a replacement."

Not sure about using the 2405 or the 2413 for pulse counting though. if you prescale the count with an external divider you still run the risk of missing counts if your polling of the 1-wire bus is not fast enough or is down for ant reason.

Hic!

[jerseyman]

I hope I am not hi-jacking this thread but ...

I can program. Started in 1969 (anyone know PLAN?) haven't stopped really.

But I know B****r all about electronics, a breadboard is for buttering my toast on. Can any one point me in the direction of "one wire for dummies" or some such?

Brian