14 Mar · Robert Eisele
RAW Things
26 Aug · Robert Eisele
Controlling High-Power Devices with Arduino and TIP120 Transistor
04 Aug · Robert Eisele
How to use the MCP4251 Digital Potentiometer with Arduino
04 Aug · Robert Eisele
Programming the ATtiny85 Using Arduino
06 Jul ·
OpenSCAD Polygons with Rounded Corners
01 Apr · Robert Eisele
jQuery color plugin xcolor
17 Aug · Robert Eisele
Catch It! HTML5 Game
10 Jul · Robert Eisele
lighttpd mod_mysql_accesslog
08 Jun · Robert Eisele
How to use a Nokia 5110 Graphical Display with Arduino
How to use a Nokia 5110 or Nokia 3310 Graphical Display using the Philips PCD8544 Controller with Arduino
13 Mar · Robert Eisele
DIY Ohmmeter to Measure Resistor values with Arduino
How to build an ohmmeter cheap and quickly with an Arduino using a voltage divider
15 Mar · Robert Eisele
Set Excel columnWidth Property in Points with VBA
How to set the Excel columnWidth property with VBA in points (centimeter and millimeter)
14 Jul · Robert Eisele
Operate a Syma S107G Remote Control Helicopter with an Arduino
A deep dive into the remote control toy helicopter Syma S107G to get controlled with an Arduino board
11 Jul · Robert Eisele
Using Gamepads in JavaScript via node.js
A node.js library to work with Sony PlayStation controllers, Microsoft XBOX controllers SNES or a bunch of other controllers
03 Jul · Robert Eisele
Set up Internet Sharing on Mac OSX using Command Line Tools
A working solution to set up internet sharing without the system preferences but command line tools
27 Jun · Robert Eisele
A pure JavaScript DHCP implementation
How to implement a DHCP server and a DHCP client in JavaScript to get access to raw packages
20 Jul · Robert Eisele
Enable Key Repeat in Mac OS-X and disable Character accent Menu
If you want to change the new behavior of showing an accent-menu instead of repeating keys in OS X, this trick may help you.
19 Dec · Robert Eisele
Using a Wii Nunchuk with Arduino
How to hack a Wii Nunchuk to make it work with Arduino
30 Nov · Robert Eisele
Creating an Advent Calendar with HTML5 and CSS3
How to create an Advent Calendar with HTML5 and CSS3 with a nice 3D effect
29 Jul · Robert Eisele
How to write a PHP Daemon
A full course into how to write a unix style daemon in PHP
08 Jul · Robert Eisele
Store a tag-cloud in MySQL
A simple approach to guide you throw the steps needed for a tag-cloud stored in a MySQL database
08 Jul · Robert Eisele
Simultaneously set and delete bit flags in a database
A proof to get to a simple expression for bit flag deletion and setting
06 Jul · Robert Eisele
Using GPS with node.js and JavaScript
An introduction to the GPS.js library
02 Jul · Robert Eisele
Complex Numbers in JavaScript
A well optimized complex numbers library in JavaScript
20 Jun · Robert Eisele
Importing entire Wikipedia into MySQL
How to import the entire Wikipedia corpus into MySQL with database installation, creation and actual import
13 Jun · Robert Eisele
Forcing Garbage Collection in node.js and JavaScript
How to force the garbage collector in node.js and V8
10 Jun · Robert Eisele
NEO6MV2 GPS Module with Raspberry PI
10 Jun · Robert Eisele
NEO6MV2 GPS Module with Arduino
Set up a serial GPS module with Arduino
12 Mar · Robert Eisele
Rational numbers in JavaScript
A rational numbers library in JavaScript for more precise calculations
05 Mar · Robert Eisele
JavaScript Bit Array
An optimized JavaScript Bit Vector Implementation
19 Aug · Robert Eisele
Running Standard Deviation in MySQL
Calculating the standard deviation without using MySQL's aggragate function STD, but by implementing it by yourself.
16 Jul · Robert Eisele
Optimal index size for variable text in MySQL
Release of a small database auxiliary query to choose the correct index size of a column.
14 Jul · Robert Eisele
Statistical functions in MySQL
A list of standard formulas for a statistical analysis with MySQL. Additionally some new functions are introduced via the infusion UDF
12 Jul · Robert Eisele
MySQL Infusion UDF for statistical analysis
An update of the MySQL infusion UDF in order to add new statistical functions to the MySQL core.
27 Oct · Robert Eisele
Flag based COUNT using MySQL
Counting flags in an optimized manner. Normally, the cardinality of flags in databases is very poor so that a different approach must be used.
24 Oct · Robert Eisele
Optimized Pagination using MySQL
How to implement an optimized pagination with MySQL?
04 Sep · Robert Eisele
jQuery Pagination revised
The best pagination plugin on the market. It combines the features of all available plugins through a distinct and easy callback interface.
10 Jun · Robert Eisele
Faster PHP behind FastCGI
A simple approach improving the performance in real world environments by reducing the number of copies of the entire DOM.
08 Jun · Robert Eisele
PHP Hacking
An extensive PHP fork with changes to the core in order to improve performance, usability and flexibility.
20 Jan · Robert Eisele
Find friends of friends using MySQL
A list of MySQL views to get the friends of friends (FOF) from a certain user of a social network.
14 Aug · Robert Eisele
Tag Cloud plugin for Smarty
An extensive Smarty plugin to create tag clouds based on some simple metrics.
12 Jan · Robert Eisele
Create a simple and small GIF with PHP
A small PHP function to create the smallest GIF possible by the standard in any color you'd like.
10 Jan · Robert Eisele
Is it possible to avoid query parsing inside of MySQL?
A question to the MySQL community...
17 Nov · Robert Eisele
MySQL - My new playground
A MySQL UDF to simplify some queries handling with binary, string and group data in a special way.
08 Nov · Robert Eisele
Transparent query layer for MySQL
A query abstraction layer which uses a prepared statement similar approach to inject cluster management transparently.
17 Sep · Robert Eisele
Camara support in HTML5 and JavaScript
Native webcam support for HTML5 by using a bridge to Flash in order to solve the technological gap
02 Sep · Robert Eisele
Resolve many-to-many relations a bit different with MySQL
An attempt to store a CSV list of ID's instead of a fully normalized table design to improve index size and to save grouping.
21 Jul · Robert Eisele
SQL-modes right to exist
An analysis of whether MySQL's SQL mode has still a right to exist. Result: It depends!
19 Jul · Robert Eisele
Use MySQL binlog to collect accesslogs
A lighttpd plugin to use MySQL's replication mechanism to collect accesslogs from several webservers.
07 Jul · Robert Eisele
My jQuery Playground
Two new jQuery plugins just arrived. A color calculation plugin and a plugin to manage your border radius
29 Jun · Robert Eisele
Combine CSS and JavaScript with lighttpd
An approach of combining static data on the fly using lighttpd's mod_magnet to reduce the number of requests.
28 Jun · Robert Eisele
Optimized way of getting subqueries at once using JSON
Retrieving nested data with a single query using JSON as the transport layer.
07 Jun · Robert Eisele
Disable ON UPDATE CURRENT_TIMESTAMP in MySQL
How to avoid triggering ON UPDATE CURRENT_TIMESTAMP in MySQL?
04 Jun · Robert Eisele
Analyze online behavior with MySQL and PHP
An algorithm to determine when users of a website or a community are mostly online in average.
29 Apr · Robert Eisele
Optimizing integer multiplication
A mathematical approach of optimizing integer multiplications for slow MUL instructions and known constants.
28 Apr · Robert Eisele
Dynamic thumbnail generation on the static server
Images are needed in several sizes on a website. Generating every file consumes a lot of disk space. Caching only the sizes they are really requested might be better.
08 Apr · Robert Eisele
Write data asynchronously to MySQL
What is the most effective way of writing data asynchronous to the database? APC queue, file based queue, Gearman, zeromq, all of them have it's right to exist.
24 Mar · Robert Eisele
Generate client-side PNG files using JavaScript
A pure JavaScript implementation of PNG to draw images directly in the browser without a canvas.
17 Feb · Robert Eisele
My very first Chrome experiment
A little HTML5 game which shows the capabilities of the new HTML5 canvas object.
27 Dec · Robert Eisele
MySQL Wishlist
My open feature request to the MySQL database server.
27 Dec · Robert Eisele
Sorted Array to MySQL
Retrieving a sorted list from a database is easy. But how do you store a list of numbers in the same order like in an array to MySQL?
27 Dec · Robert Eisele
Fulltext GEO Search with MySQL
Fulltext GEO search with MySQL. Additionaly, the population improves the weight for a fair ranking.
27 Dec · Robert Eisele
Debian lighttpd startup script
A small Debian bash script to startup lighttpd webserver. There is also an official one but when compiling the package for yourself you have to use your own.
27 Dec · Robert Eisele
Field size as power of two
Is there a difference in using powers of two as field size in MySQL or is this just a nerdy habit?
27 Dec · Robert Eisele
Age calculation with MySQL
How to calculate a human age based on two date values using MySQL? Here is a simple function which does this for you.
27 Dec · Robert Eisele
People near you with MySQL
Find locations around location with an optimized R-Tree index using MySQL MyISAM.
27 Dec · Robert Eisele
PHP Enhancement
A PHP library which adds a bunch of new functions to the core, which could be found in the one or the other project as global addition.
27 Dec · Robert Eisele
Store small numbers in big numbers
A small mathematical digression about storing small numbers in a larger bit range to save memory, disk space and index sizes.
25 Oct · Robert Eisele
How I've got no new .de domain
My fabulous attempt of getting no new 2-3 digit .de Domain. But I ended up with a nice research on weighting good names.
23 Oct · Robert Eisele
Write a PID file in bash
How to write a PID file and spawning a daemon in one single command?
30 Sep · Robert Eisele
Fast circular buffer in MySQL
A simple ring buffer implementation in MySQL with an optimization attempt to max out the performance of the fix sized buffer.
26 Sep · Robert Eisele
Global Constants with PHP
A flexible constant management library for PHP which helps to implement a centralized and easy configuration of your application servers.
25 Jul · Robert Eisele
Simple System monitoring with PHP
A simple PHP extension to tell reverse proxys and loadbalancers that the backend is overloaded. The extension sits between the PHP core and the script.
24 Jul · Robert Eisele
Add HTTP Response Headers in lighttpd
A simple FastCGI programm to add response headers to lighttpd when PHP and LUA isn't an option.
22 Jul · Robert Eisele
Face detection with PHP
PHP Facedetect Extension. The OpenCV wrapper for PHP allows you to detect faces on images and to retrieve their X/Y coordinates.
21 Jul · Robert Eisele
Get the last percents out of lighttpd
A simple lighttpd path which improves the internal constant string handling. The patch is already implemented in the stable release.
21 Jul · Robert Eisele
Logical operations with NULL
NULL values have different meanings in PHP and MySQL. Here's a little explanation after a short analysis.
20 Jul · Robert Eisele
Punycode with PHP
A libidn wrapper for PHP which allows you to generate Punycode from Unicode through a simple API.
14 Mar · Robert Eisele
HTML Particleline
14 Mar · Robert Eisele
HTML5 Boomshine
14 Mar · Robert Eisele
Play classic Snake Game Online
14 Mar · Robert Eisele
Follow the Swarm
14 Mar · Robert Eisele
3D Wire Creator
14 Mar · Robert Eisele
Starship Shooter
14 Mar · Robert Eisele
Winamp Equalizer
14 Mar · Robert Eisele
Bubble Drag
14 Mar · Robert Eisele
Bubble Evolution
14 Mar · Robert Eisele
PHP Infusion Extension
14 Mar · Robert Eisele
PHP Defcon Extension
14 Mar · Robert Eisele
PHP Sysload Extension
14 Mar · Robert Eisele
PHP Facedetect Extension
14 Mar · Robert Eisele
PHP IDNA Extension
09 Mar · Robert Eisele
Precise 220V AC Frequency Measurement with Arduino
16 Dec · Robert Eisele
Play HTML5 Tetris with AI
HTML5 Tetris is a fully customizable Tetris game with optional AI feature.
16 Dec · Robert Eisele
HTML5 Kinematic Clock
14 Jul · Robert Eisele
Trackball Rotation using Quaternions
The Arcball or Trackball is an elegant and intuitive input method to rotate and manipulate a three-dimensional scene with the mouse. With Trackball.js it is easy to integrate intuitive 3D rotations in your website using CSS3 transforms.