Close ticket 1131
dpnsw at optusnet.com.au
Wed Feb 12 23:33:00 CET 2003
I have raised a ticket about not being able to find how to get the i2c-pcf-epp
module. Ticket number 1131. This can be closed as I now know where it is and
why it is this way.
Maybe you could consider adding a bit of text on the page
under the single paragraph of explanation for the diagram.
I offer the following for comments, suggestions and corrections. It is
something that I feel would have helped me a great deal as I sought to
understand the lm_sensors project and would have also avoided me raising 2
So here goes::
The program rectangle is made up of the lm_sensors userspace programs and
configuration and documentation files.
Examples of which are:
and associated man pages
As you can see from the diagram this is only a small part of a working
lm_sensors installation. The rest of the work is done inside the kernel by
two branches of lm_sensors that work together, one is called sensors (or
should that be sensors2) while the other is i2c. You will need both in order
to fully utilise lm_sensors. Depending on what kernel you are using (or more
specifically what kernel your distribution has provided to you) will
determine what lm_sensors is capable of doing. If you find that you cannot
address all of the sensor chips you have or maybe you can't even get
i2cdetect to see your adaptor chip then you should check to see if lm_sensors
supports your hardware on
If your hardware is supported but your current kernel/distribution isn't
working then you will probably have to patch and compile the kernel.
You could just download the latest kernel version from www.kernel.org or get
the sources from your distribution. If you do this and compile it, being
carefull to configure all the devices you need, you should be aware that even
the latest kernel from kernel.org does not have all of the supported sensors
and chips in it. To enable a kernel from kernel.org to support all of the
sensors, algorithms and adaptors that it is capable of you will need to patch
the kernel. Patches are available from http://home.attbi.com/~ac9410/ for the
later 2.4 series kernels.
You can apply patches by:
path -p1 -E < path_to_the_patches/2.4.20-sensors-1-patch
Do the same for all the sensors and i2c patches you downloaded.
Note: As patches are prepared against kernels from kernel.org if you are
patching against your distribution specific source code there is a
possibility that the patches won't cleanly apply. If this is the case you can
either try and resolve it manually (if you are capable of doing this), get a
kernel from kernel.org or give up and go and do something else.
Detailed information about compiling & patching the kernel is available at
A note about algorithm and adaptor code:
Most code for algorithm and adaptors are combined into the one module as you
need both in order to be able to function correctly. There are a couple of
exceptions to this in the form of parallel port adaptors.
Parallel port adaptors
Most people don't need to worry about this.
If you are installing parallel port adaptors it means you are probably messing
around with wires and IC's and the like. If you have purchased a card that
provides external an external i2c/smbus this will have combined algorithm and
adaptor code. If you are doing it yourself by using the parallel port there
are basically 2 options.
1) Using the parallel port and using the i2c-pport adaptor module and the
i2c-algo-bit algorithm module together to enable you to wire up your parallel
port to act as an i2c/smbus. This provides a bus that will enable most
sensors to work but doesn't support the entire i2c/smbus capability
2) Using the parallel port to interface to a Philips PCF8584 parallel to i2c
adaptor chip. You will need to build a bit of a circuit to do this. This
configuration needs the i2c-pcf-epp adaptor module and the i2c-algo-pcf
algorithm module. This support almost all of the i2c/smbus capabilities
Okay that's it. Did I get it mostly right?
Turned out a bit longer than I expected. Feel free to use, change or omit as
you feel appropriate.
Many thanks for all your efforts and the project. It is really great (be even
better when I get it working ;)
More information about the lm-sensors