Skip to content

Latest commit

 

History

History
73 lines (62 loc) · 3.37 KB

systemd_install.md

File metadata and controls

73 lines (62 loc) · 3.37 KB
Raw

Installing pi-fan

Hooking into systemd

Assuming you have a working pi-fan executable, you will want to hook it into your system so that pi-fan starts automatically when your Pi boots. The way to do that is to hook pi-fan into systemd. Note that installing pi-fan requires root-permissions.

Here's the steps (all performed as root, either by doing a sudo su or by running the necessary commands via sudo <whatever command>).

  1. Copy pi-fan to a suitable system folder on your Pi, e.g. to /usr/local/bin or whatever your fancy may be.
  2. Copy the systemd service unit (systemd/pi-fan.service) to /etc/systemd/system/ on your Pi.
  3. Modify the line ExecStart=/usr/local/bin/pi-fan in the service unit file to match the spot where you placed pi-fan.
  4. Run the command systemctl start pi-fan from the command line (still as root)

That's it. Pi-fan should run, and your fan start spinning. Pi-fan will automatically start when you (re-) boot your Pi.

You can start and stop pi-fan via systemd using these commands (with root credentials)

-- Run these commands with root permissions --
# systemctl start pi-fan
# systemctl stop pi-fan

Configuring pi-fan

Pi-fan can be configured via a number of command line arguments. Execute pi-fan --help to see the possible arguments:

pi:~ $ pi-fan --help
Usage: pi-fan [OPTION...]
pi-fan is a small server that controls fan speed based on the core temperature.
It uses a GPIO pin to generate a 24KHz PWM signal that can control (almost) any
fan that has a PWM control input. Valid ranges and default values for
parameters are shown as [<from-to>/<default>].
Example: [1-30/2] means that legal values are 1 to 30 (inclusive) and the
default value is 2.
NOTE: If you send a running pi-fan instance a SIGHUP signal, it will run the
fan in a test pattern (from 0-100%) for a few cycles. You can use this for test
or demo purposes.

  -a, --maxtemp=MAX_TEMP     Temp where fan level is set at max (100%)
                             [0-100/55]
  -e, --exitlevel=EX_LEVEL   Level set for fan at program exit [0-100/50]
  -f, --foreground           Run program in foreground (for diagnostics)
  -g, --avgsample=SAMPLES    Samples for average temp [1-10/5]
  -i, --mintemp=MIN_TEMP     Min. temp before fan level increases [0-100/30]
  -l, --minfanlevel=MIN_FAN  Min. fan level (fan will never go lower)
                             [0-100/20]
  -p, --sampleper=SECONDS    Sample period in secs [1-30/2]
  -?, --help                 Give this help list
      --usage                Give a short usage message
  -V, --version              Print program version

Mandatory or optional arguments to long options are also mandatory or optional
for any corresponding short options.

Making your configuration persistent

If you want to make pi-fan use settings that differ from the defaults, you must edit the systemd unit file (pi-fan.service). Simply add the parameters to the command line for pi-fan (the line with ExecStart=/<...path...>/pi-fan).

Example: Say you want to change the fan level that pi-fan sets when it exits, to 70%. So you would change

# Line in pi-fan.service before
~
ExecStart=/usr/local/bin/pi-fan
~
# is changed into this:
~ 
ExecStart=/usr/local/bin/pi-fan --exitlevel=70
~

Restart pi-fan if you make any changes to the .service file:

-- Run this commands with root permissions --
# systemctl restart pi-fan