Tomasz Korwel
programmer, administrator, engineer – my everyday fights with reality

As I needed to have my home HVAC server always reachable and keeping in mind that it’s on a dial-up connection (dynamic IP) I decided to build virtual private network. The main goal is to get the home computer visible from the server as it was in local network. Don’t worry, it’s much easier than it seems. Thanks to detailed HOWTO it took me less than 1h to build working connection.

As it’s to easy to do and to long to describe I won’t post detailed description. Just go to the howto and follow the instructons step by step.

Here is small help and instruction howto install OWFS on new, out of the box Ubuntu 6.06 server edition.

1. Dependencies

First off all we need to take care of some needed packets:

comp# apt-get install \
       automake \
       autoconf \
       autotools-dev \
       gcc \
       g++ \
       libtool \
       libusb-dev \
       fuse-utils \
       libfuse-dev \
       swig \
       python2.4-dev \
       tcl8.4-dev \
       php5-dev

Agree for all additional needed packages apt will want to install

2. OWFS

Thanks to having fuse libraries already instaled we can go directly to the final step. First download the sourse.

comp# cd /usr/src
comp# wget http://umn.dl.sourceforge.net/sourceforge/owfs/owfs-2.4p3.tar.gz

Then extaract the file

comp# tar zxpf owfs-2.4p3.tar.gz

Compile and install

comp# cd owfs-2.4p3
comp# ./configure
comp# make && make install

3. Mounting one wire file system

First make sure that fuse kernel module is loaded

comp# modprobe fuse

It good to put it in /etc/modules file to have it automatically loaded during every system startup.

Then create the directory where 1-Wire filesystem will be mounted.

comp# mkdir /var/1-Wire/mnt

Finally we can connect our sensors to that point. In this case 1-Wire hardware is connected to the COM1 (ttyS0).

comp# /opt/owfs/bin/owfs /dev/ttyS0 /var/1-Wire/mnt

Now check if there are files and directories representing our sensors structure:

comp# ls /var/1-Wire/mnt
09.CF9EC8010000
10.64502F000800
alarm
bus.0
simultaneous
statistics
structure
system
uncached

Looks like everything is ok. The 10.64502F000800 (and all xx.yyyyyyyyyyyy) directory represents device on our 1-Wire architecture. First two characters define device family (10 – temperature sensor) the 12 characters after dot represents unique device serial number. You can go into that directory and check more properties of that particular sensor:

comp:/var/1-Wire/mnt/10.64502F000800# ls
address
family
power
r_id
temphigh
trimblanket
crc8
id
present
r_locator
templow
trimvalid
die
locator
r_address
temperature
trim
type

For detailed description of all parameters visit OWFS web site. To make sure our system is working – one last check:

comp:/var/1-Wire/mnt/10.64502F000800# cat temperature
75.3125

Looks good. Now it’s time to run some data collection thing to make those thing more usefull.

Technorati Tags: OWFS, 1-Wire, sensors, 1-Wire architecture

I’ve spent almost whole night and half of today’s morning to get it to work on Ubuntu. Detailed report later – now for those who are interested live (refreshed every 15 minutes) temperature readings from our house:

If the time scale looks like they are outdated – probably they are – it may simple means that laptop lost network connection :-). But don’t worry – they will be updated