---
id: 1032
title: Saving power of powerful printers
date: 2018-07-01T17:14:46+00:00
author: xro
layout: post
guid: http://wp.realraum.at/?p=1032
permalink: /2018/07/saving-power-of-powerful-printers/
responsive_meta_box_designation:
  - 
responsive_meta_box_facebook:
  - 
responsive_meta_box_twitter:
  - 
responsive_meta_box_googleplus:
  - 
responsive_meta_box_text_linkedin:
  - 
snap_isAutoPosted:
  - 1530458086
snap_MYURL:
  - 
snapEdIT:
  - 1
snapTW:
  - 's:380:"a:1:{i:0;a:12:{s:2:"do";s:1:"1";s:9:"msgFormat";s:15:"%TITLE% - %URL%";s:8:"attchImg";s:1:"1";s:9:"isAutoImg";s:1:"A";s:8:"imgToUse";s:0:"";s:9:"isAutoURL";s:1:"A";s:8:"urlToUse";s:0:"";s:4:"doTW";i:0;s:8:"isPosted";s:1:"1";s:4:"pgID";s:19:"1013729835691233280";s:7:"postURL";s:55:"https://twitter.com/realraum/status/1013729835691233280";s:5:"pDate";s:19:"2018-07-02 10:23:21";}}";'
categories:
  - english
  - Projekte
  - realraum News
---
At home, my Samsung laser-printer uses 15W during standby. So, a few years back, in order to save power, I put it on a USB-controlled power-plug. Pretty soon I added a tiny script that would query cups if a print-job was queued and would switch the printer on and afterwards off again. It turned out to be a pretty effective power saving measure.

<p style="height:150px;">
  <img src="http://wp.realraum.at/wp-content/uploads/2018/07/usbpowerswitching-300x148.jpg" alt="usbpowerswitching" width="300" height="148" class="alignleft size-medium wp-image-1035" />
</p>

Our two very big and reliable printers at realraum were even more power hungry, so I wanted to to something similar for the space.

Using the hardware I had on hand, I cobbled together the following:

* A BeagleBone Green to act as cups print-server and to run the python scripts.
  
* An empty 230V power-plug case, housing a 5V power-supply (for the BB) and a small opto-coupler isolated relay to switch the plug.
  
* A second power-plug case with a second small opto-coupler isolated relay.

While there is a lot of room for optimization, like a leaner BeagleBone image and better housing for the power-plugs, printing- and power-saving-wise it works very well.

As always you can find our <a href="https://github.com/realraum/printerbone" title="Code on Github" target="_blank">code on Github.</a> Stay tuned for updates.