WordPress “Internal server error”

You may experience an “Internal server error” on the home page of your site if you are a customer of iPower. You cannot access the home page nor login to

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3D Printing Supply Estimator

A GCode Analyzer for 3D printing is now available. This on-line tool estimates the amount of filaments required and the cost to print a 3D object. Give the filament type,

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Accessing a serial port from a web server

On most Linux distribution, it is impossible to access a serial port (ex. /dev/ttyS0) from a web server such as Apache or lighttpd using a cgi. Simply add the user

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Script listing all the keys on a memcache server

This script lists all the keys on a memcache server. #!/bin/bash nc localhost 11211 > /tmp/$$.1 <<EOF stats items EOF cut -d: -f2 /tmp/$$.1 | grep -v END | uniq

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Preventing warping when printing 3D ABS objects

The biggest issue when printing 3D ABS objects is warping. As an example, this 8 cm x 8 cm bit holder is badly warped. In this example, 5 mm. Adding

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VirtualBox does not run or runs slowly under Windows 8

Windows 8 comes with Hyper-V pre-installed.  If you want to run Virtual Box, you must completely uninstall Hyper-V through the “Add and Remove Programs” option from the Control Panel.  Failing

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Cannot reach 110 Celsius with a Prusa PCB Heated Bed Mk 1

I was not able to reach 110 Celsius with a Prusa PCB Header Bed MK1. My initial installation was with the PCB traces down with a borosilicate glass on top

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G-Code commands supported by Marlin

The G-Code commands supported by Marlin 3D printing firmware are: Implemented Codes G0 Rapid Motion G1 Coordinated Movement X Y Z E G2 CW ARC G3 CCW ARC G4 Dwell

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Enable the TRIM command on Mountain Lion for SSD drives

To know if TRIM is enabled for a particular drive, open “System Profiler” and search for the “TRIM enable” information in the “Serial ATA sub-tree”. If TRIM is not enabled,

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Building a Prusa Mendel Iteration 2 3D Printer

It is not obvious to choose and get a 3D printer. There is quite a lot a choices on the market which can be divided in two categories: pre-assembled and

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Ralink RT5572 based WiFi Usb Dongle setup on Ubuntu 12.04

The WiFi USB dongles based on the newest RT5572 chip set do not work out of the box on Ubuntu.  Unex DNUR-V72, D-Link DWA-160 Rev B and TP-Link TL-WDN3200 dongles are

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2.4 GHz WiFi channels

Channel Center Frequency (GHz) 1 2.412 2 2.417 3 2.422 4 2.427 5 2.432 6 2.437 7 2.442 8 2.447 9 2.452 10 2.457 11 2.462 12 2.467 13 2.472

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Recording a terminal session under Linux

It is possible to record a terminal session under Linux with ttyrec. It also records vi, emacs, etc. sessions. Fisrt, install ttyrec sudo apt-get install ttyrec To start recording a

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A step by step guide to setup a Bluetooth keyboard and mouse on the Raspberry PI

A lot of people is having problem setting up a Bluetooth keyboard and mouse on the Raspberry PI. Things get more complicated when your wired keyboard or mouse does not

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Initializing A Wireless Connection At Boot Time

You can initialize your Raspberry PI wireless connection automatically at boot time if the instructions given in a previous post entitled How To Setup A Protected Wireless Connection Via The

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How To Setup A Protected Wireless Connection Via the Command-Line

Setting up a wireless connection via the command line may vary depending on the USB Wireless Interface you are using. These instructions also work for the Raspberry PI running Wheezy.

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Masquerading or replacing outgoing SMTP email address with Postfix

Postfix can replace an outgoing email address by another one. To do so, you must perform these steps: Add in /etc/postfix/main.cf the following line smtp_generic_maps = hash:/etc/postfix/generic_maps Add in hash:/etc/postfix/generic_maps a

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Create an ext3 or an ext4 partition without a journal

Most of the time, having a journal for ext3 and ext4 partitions is pretty useful. Nevertheless, you can prevent creating a journal by adding the option ^has_journal. For example: mkfs

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Initializing a brand new disk with “parted”

“parted” is a replacement for “fdisk” of Linux.  It can handle disks larger than 2 TB.  Issue this command to launch “parted” where /dev/sdL is the disk you want to

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How to download Android source code

Source code of Android can be downloaded by following these steps: $ mkdir ~/bin $ PATH=~/bin:$PATH $ curl https://dl-ssl.google.com/dl/googlesource/git-repo/repo > ~/bin/repo $ chmod a+x ~/bin/repo $ mkdir WORKING_DIRECTORY $ cd

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