If you use linux in your macbook, you may notice that it gets quite hot, while keeping the fan speed low, to handle this issue i've develop this very simple shell utility that will read the higher temperature of your sensors (TCPD) and controll the fan speed accordingly.
It's a simple shell, with static system paths, so please modify as you need, on monitor.sh you' ll find:
# initial temperature, which this script will start to act
INI_TEMP=59
# maximum temperature your system should operate
MAX_TEMP=89
# minimum fan speed your system will operate
MIN_RPM=2100
# maximum fan speed your system should operate
MAX_RPM=5000
# not in use currently
SAV_RPM=5880
The script uses the sensors command to grep the current higher temperature, so you must have this command available in your system, sensors should give you an output similar to this one:
applesmc-isa-0300
Adapter: ISA adapter
Exhaust : 3536 RPM (min = 3539 RPM, max = 6200 RPM)
TA0P: +42.8°C
TB0T: +36.8°C
TB1T: +36.8°C
TB2T: +35.2°C
TC0E: +56.2°C
TC0F: +58.0°C
TC0J: +1.8°C
TC0P: +50.2°C
TC1C: +55.0°C
TC2C: +55.0°C
TCGC: +54.0°C
TCSA: +55.0°C
TCTD: -0.2°C
TCXC: +55.5°C
TG1D: +58.0°C
TM0P: +40.5°C
TM0S: +48.0°C
TPCD: +63.0°C
Th1H: +44.5°C
Ts0P: +32.2°C
Ts0S: +39.5°C
coretemp-isa-0000
Adapter: ISA adapter
Package id 0: +59.0°C (high = +87.0°C, crit = +105.0°C)
Core 0: +57.0°C (high = +87.0°C, crit = +105.0°C)
Core 1: +59.0°C (high = +87.0°C, crit = +105.0°C)
BAT0-virtual-0
Adapter: Virtual device
temp1: +37.1°C
With this output you'll be able to identify the sensor with the higher temperature, which will probably the CPU / GPU, in my case this sensor was the TCPD which is used in the grep command.
Also, the system file which controls the fan speed may change depending of your hardware, for me it is:
/sys/devices/platform/applesmc.768/fan1_min
If you cat this file, you'll see it has only one number, which is the fan RPM.
The final step it's to add a crontab entry, to execute this script every minute, and by doing so, keep the fan speed updated according with your usage, this entry has to be added in your super user account, so that you have rights to change the contens of your fan speed file.
Login with your super user and type crontab -e
Insert this line changing the path to your monitor.sh
* * * * * sh /home/gritt/Projects/mbp-fancontrol/monitor.sh
You can monitor how your fan speed changes by watching the sensors command: watch sensors
And your done!
Please proceed with caution, you don't wanna set your fan speed to zero and damage your computer, so, test this script in an empty file, read, modify, and understand the contents before executing it.