From 0501c97b57f3331b0480c73c2b385a2ebabe6744 Mon Sep 17 00:00:00 2001 From: Marius Reiner Date: Sat, 27 Sep 2003 14:52:55 +0000 Subject: [PATCH] (marius) linewrap git-svn-id: http://lm-sensors.org/svn/lm-sensors/trunk@2006 7894878c-1315-0410-8ee3-d5d059ff63e0 --- doc/fancontrol.txt | 68 ++++++++++++++++++++++++++++++++-------------- 1 file changed, 47 insertions(+), 21 deletions(-) diff --git a/doc/fancontrol.txt b/doc/fancontrol.txt index f5c32b8b..d05326d9 100644 --- a/doc/fancontrol.txt +++ b/doc/fancontrol.txt @@ -1,29 +1,43 @@ + fancontrol - automated software based fan speed regulation Introduction -fancontrol is a shellscript for use with lm_sensors. It reads its configuration from a file, then calculates fan speeds from temperatures and sets the corresponding pwm outputs to the computed values. -It is included in lm_sensors since 2.8.0, the latest version is always available through CVS or at http://www.hdev.de/fancontrol/ -For easy configuration, there's a script named pwmconfig which lets you interactively write your configuration file for fancontrol. Alternatively you can write this file yourself using the information from the configuration section of this document. +fancontrol is a shellscript for use with lm_sensors. It reads its +configuration from a file, then calculates fan speeds from temperatures and +sets the corresponding pwm outputs to the computed values. It is included in +lm_sensors since 2.8.0, the latest version is always available through CVS or +at http://www.hdev.de/fancontrol/ For easy configuration, there's a script +named pwmconfig which lets you interactively write your configuration file for +fancontrol. Alternatively you can write this file yourself using the +information from the configuration section of this document. -Please be careful when using the fan control features of your mainboard, in addition to the risk of burning your CPU, at higher temperatures there will be a higher wearout of your other hardware components, too. So if you plan to use these components in 50 years, _maybe_ you shouldn't use fancontrol/your hardware at all. -Also please keep in mind most fans aren't designed to be powered by a PWMed -voltage, for more detailed information on this I recommend this app-note: -http://www.maxim-ic.com/appnotes.cfm/appnote_number/707 +Please be careful when using the fan control features of your mainboard, in +addition to the risk of burning your CPU, at higher temperatures there will be +a higher wearout of your other hardware components, too. So if you plan to use +these components in 50 years, _maybe_ you shouldn't use fancontrol/your +hardware at all. Also please keep in mind most fans aren't designed to be +powered by a PWMed voltage, for more detailed information on this I recommend +this appnote: http://www.maxim-ic.com/appnotes.cfm/appnote_number/707 In practice it doesn't seem to be a major issue, the fans will get slightly -warm, just be sure to have a temperature alarm and/or shutdown call, in case +warmer, just be sure to have a temperature alarm and/or shutdown call, in case some fan fails, because you probably won't hear it anymore ;) Configuration -Since most of you are going to use the pwmconfig script, the config file syntax will be discussed last. First I'm going to describe the various variables available for changing fancontrol's behaviour: +Since most of you are going to use the pwmconfig script, the config file +syntax will be discussed last. First I'm going to describe the various +variables available for changing fancontrol's behaviour: INTERVAL - This variable defines at which interval in seconds the main loop of fancontrol will be executed + This variable defines at which interval in seconds the main loop of + fancontrol will be executed FCTEMPS - Maps pwm outputs to temperature sensors so fancontrol know which temperature sensors should be used for calculation of new values for the corresponding pwm outputs. + Maps pwm outputs to temperature sensors so fancontrol know which + temperature sensors should be used for calculation of new values for + the corresponding pwm outputs. MINTEMP The temperature at which the fan gets switched off completely. @@ -32,30 +46,42 @@ MAXTEMP The temperature at which the fan gets switched to full speed. MINSTART - Sets the minimum speed at which the fan begins spinning. You should use a safe value to be sure it works, even when the fan gets old. + Sets the minimum speed at which the fan begins spinning. You should + use a safe value to be sure it works, even when the fan gets old. MINSTOP - The minimum speed at which the fan still spins. Use a save value here, too. + The minimum speed at which the fan still spins. Use a save value here, + too. -If you set up your configuration by hand, be sure to include ALL variables and use valid values, there's no error handling yet! The file format is a bit strange: +If you set up your configuration by hand, be sure to include ALL variables and +use valid values, there's no error handling yet! The file format is a bit +strange: -VARIABLE=chip/pwmdev=value chip/pwmdev2=value2 [...] -VARIABLE2=[...] +VARIABLE=chip/pwmdev=value chip/pwmdev2=value2 [...] VARIABLE2=[...] -Each variable has its own line. The variable name is followed by an equal sign and the device=value pairs. These consist of the relative path to the pwm output (from /proc/sys/dev/sensors/) for which the value is valid, equal sign followed by the value and are seperated by a blank. +Each variable has its own line. The variable name is followed by an equal sign +and the device=value pairs. These consist of the relative path to the pwm +output (from /proc/sys/dev/sensors/) for which the value is valid, equal sign +followed by the value and are seperated by a blank. Example: MINTEMP=w83627hf-isa-0290/pwm2=40 w83627hf-isa-0290/pwm1=54 -You have to play with the temperature values a bit to get happy. For initial setup I recommend using the pwmconfig script. Small changes can be made by editing the config file directly following the rules above. +You have to play with the temperature values a bit to get happy. For initial +setup I recommend using the pwmconfig script. Small changes can be made by +editing the config file directly following the rules above. The algorithm -fancontrol first reads its configuration, writes it to arrays and loops its main function. -This function gets the temperatures and fanspeeds from lm_sensors proc files and calculates new speeds depending on temperature changes, but only if the temp is between MINTEMP and MAXTEMP. After that, the new values are written to the pwm outputs. -Currently the speed increases quadratically with rising temperature. This way you won't hear your fans most of the time at best. +fancontrol first reads its configuration, writes it to arrays and loops its +main function. This function gets the temperatures and fanspeeds from +lm_sensors proc files and calculates new speeds depending on temperature +changes, but only if the temp is between MINTEMP and MAXTEMP. After that, the +new values are written to the pwm outputs. Currently the speed increases +quadratically with rising temperature. This way you won't hear your fans most +of the time at best. Planned features