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FAND(8) System Manager's Manual FAND(8) NAME fand -- daemon to control PWM (Pulse Width Modulation) cooling fans SYNOPSIS fand [options...] temperature_sensor pwm_device fand [-s] [options...] temperature_sensor pwm_device DESCRIPTION The fand daemon can be used to control a cooling fan connected to a pwmc(4) pwm_device based on the system temperature retrived from a sysctl(3) temperature_sensor PWM parameters. temperature_sensor should be the name of the sysctl variable used to read the system temperature. pwm_device should be the name of the PWM device that controls the system fan. If an unqualified name is pro- vided, /dev/pwm is automatically prepended. When called with the -s option, fand will print the current status of the temperature sensor and the PWM state and exit. This can be useful when determining the required temperature multiplier and other options. The options are as follows: -d duty The duty cycle (in nanoseconds or percentage) of the PWM channel for the default (low) temperature thresh- old. Duty is the portion of the period during which the signal is asserted. -D duty The duty cycle (in nanoseconds or percentage) of the PWM channel for the high temperature threshold. Duty is the portion of the period during which the signal is asserted. -f Run fand in the foreground. Also enables more verbose output. -i seconds The temperature polling interval, in seconds (Default: 60) -I Invert PWM signal polarity -K Converts the temperature sensor reading from degrees Kelvin -m multiplier Multiplier applied to reading from temperature sensor (Default: 1.0) -o temperature Temperature to deactivate fan, in C (Default: 50) -p period The period in nanoseconds of the PWM channel for the default (low) temperature threshold (Default: 0) -P period The period in nanoseconds of the PWM channel for the high temperature threshold (Default: 0) -r path The PID file path (Default: /var/run/fand.pid) -s Show current temperature and PWM status, then exit. -t temperature Default (low) temperature to enable the fan, in C (De- fault: 50) -T temperature High temperature threshold, in C (Default: not set) -v Print program version and exit EXAMPLES • Using the "hw.temp.CPU" sensor and the pwmc1.0 controller, run the fan at half duty cycle when the temperature reaches 45C and run at full when the temperature rises above 60C. Disable the fan if the temperature falls below 35C. When reading from the sensor, assume value is in tenth degrees Kelvin. fand -t 45 -p 50000 -d "50%" -T 60 -o 35 -K -m 0.1 hw.temp.CPU pwmc1.0 SEE ALSO sysctl(8), pwm(8) AUTHORS The fand utility and this manual page were written by Corey Hinshaw <corey@electrickite.org>. fand 0.2.3 February 10, 2022 FAND(8)
NAME | SYNOPSIS | DESCRIPTION | EXAMPLES | SEE ALSO | AUTHORS
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