Temperature sensor / weatherstation

Create a weatherstation or temperature monitor using the very cool digital temperature sensor DS1820.

I use this setup to monitor a server room, and as a weatherstation.

This project consists of:

• A Dallas 1-Wire bus network
• Interface between RS-232 and the Dallas 1-Wire system
• Digital temperature sensors connected to the Dallas 1-Wire bus (DS1820/DS18s20)
• Software setup to gather and graph temperatures

Updated 2007-11-18 to include automatic graphing scripts and pictures of real life implementations of this system.

Step 1 You need

This is what you need to make a weather station or temperature logger:

• Some linux skills
• Basic electronics skills, soldering etc..

Components

• 1 6.2V Zener diode (1N5234)
• 1 3.9V Zener diode (1N5228)
• 2 Schottky diodes (1N5818)
• 1 1.5 k resistor
• 1 2pin screw terminal
• 1 D-sub 9 female connector with solder points
• 1 small piece of perfboard.
• One or more Dallas Semiconductor DS1820 or DS18s20 digital temperature sensor
• Cat5 cabling
• Shrink tube

Comments

[gadragon]

Can i use 1N5819 instead of 1N5818?

[humall]

I have little experience with soldering so I made a breadboard version of the circuit, see pdf file I added, I used Ubuntu for Digitemp and everything works fine, rrd-tool and web server setup. Tried to use Windows version of Digitemp, did not work. Thanks for making this instructable, it showed me how to use 1-wire bus.

[garacs]

This is EXACTLY what I am looking for, but unfortunately it uses DALLAS DS1820 sensors, I do not have handy at the moment.

Would this also work with a LM35DZ? If so, what would be the differences in the scheme?

BTW, great instructable.

[andy70707]

Will this interface work with other 1-wire devices such as iButtons? And can it do bi-directional serial (read+write) or just simply reading from the device?

[Wavy]

Great Instructable! Using a breadboard, everything worked out smoothly. I also used the MartyBugs' schematic to confirm the setup. Very nice and fun, thanks!

[titan44]

Is it possible to make this work with a db25 instead of a db9?

[Brafferton]

Db25:
Pin 2 Transmit
Pin 3 Receive
Pin 7 Ground
Pin 20 DTR (if using non-parasitic)

[mattccc]

(removed by author or community request)

[Brafferton]

Short answer is, you don't.
The 18S20 is a 1 wire serial device
Your printer port will only talk to parallel devices.

[thermoelectric]

I tried this on Linux (Ubuntu) and when I typed this into the terminal "digitemp -s /dev/ttyS0 -i" i get this

"DigiTemp v3.5.0 Copyright 1996-2007 by Brian C. Lane
GNU Public License v2.0 - http://www.digitemp.com
Turning off all DS2409 Couplers

Searching the 1-Wire LAN"

Problem is it doesn't show any sensors....

[Brafferton]

It's not physically working. Check all the components are correctly polarised (My goof was wiring the D"18S20 back to front)

[darkcape]

Loving this I have wanted to do this ever since reading about it in the linux toys book. on question I have though what is the maximum number of sensors that the 1 wire network can handle?

[Brafferton]

Depends on whether it's in parasitic mode or non parasitic. From the number of components used, I'd say it in parasitic mode. Therefore, no more than 3.
In non-parasitic mode (2 more components required) 10 or 12 would be quite happy. With a separate 5 volt PSU, several thousand.

[wareneutron]

you have to work in weather forcast

[eng_islam_h]

thats really great,i've done it and it works really fine with the 1 wire driver from maxim, now i'm trying to read the data in LabView and i'm really close
great job
thanks 

[salimi]

hi please write vb code for monitoring graph

[thermoelectric]

I don't know if I have done it right, but when I try to run the logdata script manually I get a error. What do you suggest? beau@beau-desktop:~$ php /etc/tempsensor/graphdata.php ERROR: opening '/var/log/digitemp_rrd/0.rrd': No such file or directory ERROR: opening '/var/log/digitemp_rrd/0.rrd': No such file or directory ERROR: opening '/var/log/digitemp_rrd/0.rrd': No such file or directory ERROR: opening '/var/log/digitemp_rrd/0.rrd': No such file or directory ERROR: opening '/var/log/digitemp_rrd/0.rrd': No such file or directory ERROR: opening '/var/log/digitemp_rrd/0.rrd': No such file or directory ERROR: opening '/var/log/digitemp_rrd/0.rrd': No such file or directory ERROR: opening '/var/log/digitemp_rrd/0.rrd': No such file or directory Warning: fopen(/var/www/temperature/index.html): failed to open stream: Permission denied in /etc/tempsensor/graphdata.php on line 75 Warning: fwrite(): supplied argument is not a valid stream resource in /etc/tempsensor/graphdata.php on line 76 Warning: fclose(): supplied argument is not a valid stream resource in /etc/tempsensor/graphdata.php on line 77 Warning: fopen(/var/www/temperature/index_0.html): failed to open stream: Permission denied in /etc/tempsensor/graphdata.php on line 102 Warning: fwrite(): supplied argument is not a valid stream resource in /etc/tempsensor/graphdata.php on line 103 Warning: fclose(): supplied argument is not a valid stream resource in /etc/tempsensor/graphdata.php on line 104 Warning: fopen(/var/www/temperature/index_all.html): failed to open stream: Permission denied in /etc/tempsensor/graphdata.php on line 102 Warning: fwrite(): supplied argument is not a valid stream resource in /etc/tempsensor/graphdata.php on line 103 Warning: fclose(): supplied argument is not a valid stream resource in /etc/tempsensor/graphdata.php on line 104

[bhp0528]

I'm a little shy (actually lazy) when it comes to circuit boards and solder. I noticed a similar tutorial was using a http://www.maxim-ic.com/quick_view2.cfm/qv_pk/2982 to interface from serial to RJ-45.

Looking at the documentation it appears this would do the same as your diodes and soldering and give you a RJ-45 to boot. The site appears to spec the device for $21. Any idea how that would compare to soldering diodes in price and functionality?

[bhp0528]

After looking at the site a little longer I found a number of different adapters (USB, Serial, etc). Has anyone tried these?

http://www.maxim-ic.com/products/ibutton/products/adapters.cfm#rs232

[Solargoat]

I built it, but having zero electronics experience, and not much software experience, I am not sure if it works. After downloading various programs to read it, including 1-WireViewer, Lampomittari, and I can't seem to get it to recognize my interface. I guess it is a hardware problem in how I constructed it. What can I do to troubleshoot this device with a multimeter? What is the proper voltage that should be coming out of my serial port on my Dell Latitude D620 notebook? I am getting 4.98 Volts now. If someone could get me started, I would be eternally grateful!

[Solargoat]

That was a quick reply! I have an iMac and a Gigaware USB-serial converter. I guess I'll try that, but now that will introduce its own issues with software.

[chr]

Some notebooks don't output the full RS232 voltage of +/- 12-ish volts. Try the device on a desktop computer first to figure out if the voltage level is causing the problem.

[ax89]

Very neat! How many sensors can you hook up? (I apologize if this was asked and answered but I didn't see it when I read through.)

[thermoelectric]

It will tell you how many sensors can be connected on the datasheet of the 1-wire sensor.

[thermoelectric]

Hey, I'm back. I have been able to make it run on Windows but it can't dectect my interface, Is there a way to test what I have wired incorrectly?

BTW to get it to run on windows you need to

• download the current Windows digitemp
• find the digitemp.exe file in the digitemp file
• copy that to WINDOWS/system32
• Go into command prompt and type "digitemp", That will give you the syntax of the command
  

Hope I could help anyone that is trying to use it on Windows...

[thermoelectric]

Wow, After attempting to make the interface, I can safely say that you are GREAT at using protoboards.

Do you know how I can use this on windows?
I have tried what you said below but it doesn't work, What does the digitemp -aq > c:\path\to\webserver\root\temperature.txt mean?

[chr]

Thanks, -a means aquire, -q means quiet the "> file" means put the output into this file I don't know if this is the right syntax in windows. I don't know anything about windows, so I can't help you there...

[thermoelectric]

By the way, Why do you reccommend using CAT5 cable over telephone cable?

[chr]

I had some major issues when using telephone cable. I have an installation using cat5 with about 50 meters of cable, and that one works just fine.

[thermoelectric]

Issues? What was happening with the telephone wire to cause major issues?

[thermoelectric]

Oh, Thanks anyway, I might just have to try the alternate install of Ubuntu (128mb RAM)

[thermoelectric]

That is a definite thing i'm going to have to do since I can't get it to work in windows....

[thermoelectric]

Scratch that :-)

[BCHurricane89]

looks good, nice job. just wondering, because someone asked before, and I have the same question, but it wasnt answered: Can i use a DS18S20+ sensor? the DS1820 is discontinued, and I can get the DS18S20+ free, as a sample. :) plz respond, THANKS!

[chr]

I think any DS18*20* would work. try googling the digitemp documentation..

[thermoelectric]

Yes you can use the DS18S20+ (All the + indicates is the lead free status...)

[goldust]

hi chr this tutorial is very Useful. but i want to Setup software for WindowsXP . can you help me? (i know you are Professional)

[chr]

Hehe I don't know if I'm professional. Most people who call them selves professional would probably have bought a ready made system for $5000 ;)

Anyways, I find doing these kind of things on windows to be kind of a pain.
Although most of the software is available for windows.

Digitemp is available here: http://digitemp.com/software/windows/
I would think dtreg25.zip is the most current version.
With digitemp the setup would be pretty much the same as in Linux.
Make a batch file, i.e. readtemp.bat containing a line like this:
"digitemp -aq > c:\path\to\webserver\root\temperature.txt"

There are many other programs to run 1-wire sensors on windows. A google search brings up plenty.
For example: http://www.henriksens.net/1-wire/

Good luck making it work on Windows.

Maybe I'll give it a go myself, and post a step on win32, but now I'm in the middle of my final exams.

[thermoelectric]

Have u had a go at making it run on windows?

[thermoelectric]

Can I use a DS18S20+ (i think the plus indicates the RoHS status)