Power Policy Manager FAQ

What packages do I need to install?

PPM requires the following packages:

• libglib2.0-dev
• libdbus-1-dev
• libdbus-glib-1-dev
• libhal-dev
• x11proto-xext-dev
• libx11-dev
• xbacklight
• libxrandr2 >= 1.2.0
  

How do I compile the latest PPM from source?

1. Pull from the PPM repository:
   

     $ git-clone http://www.lesswatts.org/repos/projects/ppm.git

   
   
   
2. Compile and install the code:
   

       $ cd ppm
   
       $ make
   
       # make install

   
   

How do I run PPM?

First, start the PPM daemon as root:

  # ppmd

Optionally, you may add the -f flag to run PPM in the foreground. This will send log messages to the console, rather than to /var/log/ppmd.

Next, start PPM to select the modes you want:

  $ ppm

You may want to use `ppm --help` to get more options.

What is the difference between modes, layers and commands?

See the Introduction page for a full explanation.

What is an invisible mode?

Invisible mode is hidden from user application. An invisible mode is selected on certain system events, like battery connects/disconnects.

What is the default PPM mode?

The default mode defines which layers to activate on PPM startup. The default mode file is /usr/local/ppm/modes/default.

Why doesn't my screen brightness change when I switch between battery and AC?

First, make sure you have the ACPI modules 'ac' and 'battery' loaded. Second, you need to install xbacklight and libxrandr2 (version 1.2.0 or higher). Some hardware is not yet supported by xbacklight. Also note that some laptops, like the IBM T42, will automatically dim the screen without PPM running.

How I can add my own policies?

You can create your own mode and layer files then copy them to the right directories in /usr/local/ppm.

How do I contact the developers?

The PPM developers can be found on the lesswatts IRC channel, #lesswatts on irc.oftc.net. Or you can send email to the lesswatts discussion mailing list.