Dallas 1-Wire.. Wiring

I just got a 1-wire humidity sensor and the 9097u-s09 Serial adapter… I want to run CAT5 between the sensor and the adapter… with RJ11 connectors at both ends…

How do I wire the wire?? Is it straight through? Since my phone jack has only 4 wires, are there any particular color pairs I should use to connect to these 4 wires??



NO crossover!


That is still pretty vague… I emailed them directly and haven’t heard back yet… It does say to use solid colors, green/blue and yellow/green… and since you state not to crossover… I’d have to assume that if I make a straight through cable using the above color combos… I’d be good to go!

I’ll give it a try!!!


They pulled that info from Dalsemi - use the pairs they suggest and put them straight through. BTW, I’ve tested 80 foot telco wire and it works fine.


Straight through is correct. One thing to watch out for if adding individual temperature sensors is that most RJ11 wires used on phones do a crossover. These won’t work. You need to make sure that the wire alignment enters and exits the same. I have found that often they swap.

The D1W uses only two of the wires - green as data, red as ground. If you are using parasitic power for temp sensors, then join the two outermost pins and connect the green. Center pin goes to red.

I have a humidity sensor only at this time… and I’m using Cat 5 cable… I imagine it’s what you called parasitic power, since I have no external power source…

I have it wired straight through as follows…

Brown, Blue, Green, Orange

As looking at it from the botton (pin side) of the RJ11 connector…

This will go into the 9097U-S09 which goes into the Serial port on my pc… sound okay??


Hi ,

When making up your 1-wire leads , it’s easy to remember both ends of your lead ( should match each other )
holding them up facing the same way .

eg Plug 1 RJ 12 ( 6 connections
~ blue 1/white2 , orange3/white4 , green5/white6 )

now the other end ( of the same lead )
plug 2 RJ12 ( 6 connections
~ blue 1/white2 , orange3/white4 , green5/white6 )

ALso it pays to invest in a RJ12 crimping tool and connectors ( CAT5 cable as well )

Hope this is of help :smiley:

I’ll give it a whirl! I have 4 pin RJ-11 jacks for some reason… I noticed the 9097U also has only 4 pins… the AAG 1wire humidity/temp sensor has 6 pins in it though… I’d have to guess/hope that only the 4 inner pins are used, however if that is the case, the 4 pin cable I currently have should have worked…

It’s been pretty frustrating for me… I’m not an electrician and this type of stuff is probably why!! :slight_smile:

I’ll get a couple 6 pin jacks and give that a try.

Thanks for your help!

Hello Stuntman ,

Your correct , the inner two pins are the only ones used .

RJ 11 6 pin
pin 3 data
pin 4 gnd

in your case RJ11 4 pin

pin 2 data
pin 3 gnd

Depending on who’s humidity sensor you bought ( may be part of you problem )
You may need to power it with external voltage
I think JJWARE humidity sensor requires this .

Also you can reversed you data & gnd lines without any problems
You should download the TMEX drivers first and try and see if you can view the RomID .


  1. I also have the aag humidity sensor. I thought it also came with a temperature sensor but WD doesn’t see the ID… Am I doing something wrong or is it true that it only has humidity? If it also has temp is there something in WD I need to do to see it?

In the meantime I added a DS18B20 temp sensor between the Data and Gnd inside the humidity sensor. WD sees the ID for this added sensor.

  1. Is there an issue with long wiring? The humdity data started spiking up and down every minute or so when I added perhaps 100 feet of wire. With just 10 feet of wire it’s fine. Do I need to supply VCC for long wire (and not depend on parasitic power)? I believe the aag humidity sensor is wired for parasitic powr.

Hi Ted ,

The humidity sensor comes with temperture in-built . You need to select the correct temperture RomID and allocate as a temperture ( in my case I’m using it as the main temperture ) .
the temperture was recently trending as Humtemp on the extra sensor graph ( trend No 7 ) , but with the addition of the solar sensor the default position has been taken over .

Regarding you problem with 100 feet of cable ( are you are using CAT5 cable ? ) .
The addition of a 100 ohm resistor in series with the data line ( helps with reflections in the lines , which may be causing your problems )

Is the ROM ID for the AAG Humidity sensor used for both the humidity and temperature? The reason I ask is because WD finds only the one humdity ROM ID.

I’ll try that 100 ohm resistor.



As a general rule…is it best to include a 100 ohm resistor in line with the data line? I have experienced some problems with my WD where it ‘stops’ recognizing sensors. Symptoms range from the system hanging, to it saying it recognizes temp sensors but reporting incorrect results. I have purchased my CAT5 wiring to replace my current telephone wiring but haven’t had the time to do the swap-out yet. I run a DS9097U interface using parasitic power.

I have read the various materials on the Dallas site on wiring configs and admit that my “star” configuration isn’t a good one. I am working to replace.

I was just interested in seeing the consensus on including a 100 ohm resistor in the new CAT5 setup. Is it a good idea just as a general principle to include the resistor? Has anyone implemented this in a similar environment? Are there any downsides to doing this? (I have read in one of the Dalsemi documents that the DS9097U is adversley affected by the addition of this resistor).