Remigium repository

At https://github.com/remigium there is a repository for small custom Arduino (and others) projects

Pi and energy consumption

When doing nothing the Raspberry Pi 2 takes something like 1,3W. When starting X-windows its energy consumption goes up to 2,2W, then drops to 1,8W. Almost nothing. At the same time the monitor takes something like 30W, which is much more and not the thing the tiggers like most. And while I started with Raspberry as a media center or game console, I currently would like to make it kind of information center at home, possibly being able to serve content to local display as well as to other hosts in the home network.

But for such function I would like to decrease the energy consumption as much as possible, being still able to control the Raspberry and through it also peripherals.

The monitor

As I said the monitor takes 30W, no matter it has something to display or not. But there is something which allows to change it to 1,9W while in idle time, so pretty cool.

## the command deals with HDMI events, so ...
## one may disable the monitor to sleep state
$ tvservice --off 

## below command wakes up the monitor
$ tvservice --preffered
## however one needs to reboot kodi to get it working
$ sudo /etc/init.d/kodi restart

Another possibility would be to acquire some z-wave dongle and control the display through switching it ON or OFF. But in my case this is not the best decision - it would mean to power off the USB hub built-in the monitor and all the devices attached to that hub.

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Update 2016.03.01

Today I've found quite thorough thread on the subject. As it is quite long and starts when the Kodi was XBMC, then I 've just focus on the screensaver by timker. I 've installed it from zip file and works great for me - the screen is powered off and enables on any action from mouse or keyboard, while in the background it is possible to work on Raspberry connecting through ssh. The energy consumption while the screensaver is on varies around 4W for both monitor and Raspberry.
Now I can keep Raspberry enabled all the time, while the monitor will work only when needed.

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Update 2016.03.01

I use also Raspbian and didn't find a screensaver, yet in some article I saw a script - not sure what is /usr/bin/graphical_launcher - do not have it.
Anyway even if the call to startx does not see the program in argument, yet it works as needed - the call to the script from a remote ssh session (i.e. any session) refreshes the monitor screen. Powering a monitor off is the same as above, powering on as well - main difference is call to startx rather than to kodi.
Just by the way

xset dpms force on|off

enables screen blanking - it does not power screen off (at least my Iiyama), thus energy consumption is actually not diminished.