OVERVIEW OF THE LM-SENSORS PACKAGE
==================================

The lm-sensors package, version 3, provides user-space support for the
hardware monitoring drivers in Linux 2.6.5 and later. For older kernel
versions, you have to use lm-sensors version 2.

The directories within this package:

* doc
  Documentation.
* etc
  A sample configuration file for libsensors, and a script to convert
  lm-sensors version 2 configuration files to work with version 3.
* lib
  The user-space sensors support library code (libsensors).
* prog
  Several supporting programs. The most important ones are:
  - sensors-detect: A stand-alone program for detecting installed
    hardware and recommending specific modules to load.
  - sensors: A console tool to report sensor readings and set new
    sensor limits.
  - sensord: A daemon to watch sensor values and log problems. It
    includes RRD support.
* configs
  This directory contains sample configurations of various boards,
  contributed by users of lm-sensors.

  All configuration files should now be imported from the old
  www.lm-sensors.org website, however additional information about
  the origin of the configuration files can be found on the old site:
  http://web.archive.org/web/20150901092438/http://www.lm-sensors.org:80/wiki/Configurations

  Please contribute back a configuration of your board so other users with
  the same hardware won't need to recreate it again and again.

INSTALLING LM-SENSORS
---------------------

See the INSTALL file.


HARDWARE SUPPORT
----------------

To find out what hardware you have, just run 'sensors-detect' as root.

Most modern mainboards incorporate some form of hardware monitoring chips.
These chips read things like chip temperatures, fan rotation speeds and
voltage levels. There are quite a few different chips which can be used by
mainboard builders for approximately the same results.

Laptops, on the other hand, rarely expose any hardware monitoring
chip. They often have some BIOS and/or ACPI magic to get the CPU
temperature value, but that's about it. For such laptops, the lm-sensors
package is of no use (sensors-detect will not find anything), and you have
to use acpi instead.

This package doesn't contain chip-specific knowledge. It will support all
the hardware monitoring chips your kernel has drivers for. In other words,
if you find out that you have unsupported hardware (e.g. sensors-detect
told you so) then it means that you need a more recent kernel, or you
even need to wait for a new kernel driver to be written. Updating the
lm-sensors package itself will not help.


LIBSENSORS
----------

The kernel drivers communicate their information through the /sys
interface. Because every motherboard is different, the drivers always
advert the measurements at their pins. This means that the values they
report are not always immediately relevant to you. They have to be
labelled properly, and sometimes they must be scaled to correspond to
real-world values.

libsensors is a (shared or static) library of access functions. It
offers a simple-to-use interface for applications to access the sensor
chip readings and configure them as you like. It has a configuration
file where you can put all the motherboard-specific labels and
conversion rules. That way, all applications do not need to duplicate
the effort and can simply link with libsensors and work out of the box.


APPLICATIONS
------------

This package contains an example console program that reports all current
sensors values. This program is called 'sensors'. You can use it as a
reference implementation for more intricate programs. It also contains a
daemon watching for sensor values, logging alarms and feeding an RRD
database with the sensor measurements.

This package does not contain a nice graphical monitor. See
http://sensors-applet.sourceforge.net/
https://01.org/powertop/
https://wpitchoune.net/psensor/
https://amanusk.github.io/s-tui/
for such programs.


TROUBLESHOOTING
---------------

lm-sensors is blamed for all kinds of problems on a regular basis.
While it is always possible that lm-sensors does in fact have a problem,
almost everytime the problem will be elsewhere. The most likely culprit
for a problem is one of the kernel drivers prividing data to lm-sensors
or, rather, the sensors command (and libsensors). If you encounter problems,
the following tests are recommended.

- Check enabled sensors with the 'sensors' command. Observe and, if there
  are errors, write down your test steps and report.
- If any problems are observed while running the 'sensors' command, disable
  (unload) kernel drivers one after another. After unloading a driver, run
  the 'sensors' command again and observe if the error is gone. If it is,
  you found the problematic driver. Record your tests and report to the driver
  maintainer.
- If problems are observed while using libsensors from another application,
  the same procedure applies (though it is recommended to perform the test
  with the sensors command first). Again, after identifying the offending
  driver, record and report your results to the driver maintainer.
- If this does not help, try to run ptrace on the sensors command and/or
  the application using libsensors. If you find any anormalies, record
  your results and report.


OTHER INFORMATION
-----------------

The lm_sensors website can be found at
https://hwmon.wiki.kernel.org/lm_sensors

The developers of this package can be reached using
* a mailing list lm-sensors <at> vger <dot> kernel <dot> org
  (you can get information on how to subscribe, unsubscribe, and the list
  of archives at http://vger.kernel.org/vger-lists.html#lm-sensors;
  you do not need to be subscribed to post to the list)
* GitHub (see https://github.com/lm-sensors/lm-sensors)

Do not hesitate to contact us if you have questions, suggestions, problems,
want to contribute, or just want to report it works for you. But please try to
read the documentation before you ask any questions! It's all under doc/.

The latest version of this package can always be found at:
https://github.com/lm-sensors/lm-sensors.

LICENSE
-------

The library (libsensors) is released under the GNU Lesser General Public
License (LGPL), as included in the file COPYING.LGPL. The rest of this
package may be distributed according to the GNU General Public License
(GPL), as included in the file COPYING.
