General Purpose Input/Output (a.k.a. GPIO) is a generic pin on a chip whose behavior (including whether it is an input or output pin) can be controlled (programmed) through software. The Raspberry Pi allows peripherals to access the CPU by exposing
Install Raspbian “wheezy” on Raspberry PI
To install Raspbian on a Raspberry PI you need an SD card, at least 4GB and the image of the Raspbian OS. Download the image from http://www.raspberrypi.org/downloads. The latest version of Raspbian is called “wheezy”: 2012-12-16-wheezy-raspbian.zip. Unzip file and the result is “2012-12-16-wheezy-raspbian.img”. Write
MySQL replication – master slave schema
Replication enables data from one MySQL database server (the master) to be replicated to one or more MySQL database servers (the slaves). Replication is asynchronous – slaves need not be connected permanently to receive updates from the master. This means
Raspberry PI
The Raspberry Pi is a small single-board computer developed in the UK by the Raspberry Pi Foundation with the intention of stimulating the teaching of basic computer science in schools. The Raspberry Pi is manufactured through licensed manufacturing deals with
Save Apache log in MySQL database
Apache webserver can be configured to save access logs into database via Apache Module mod_log_config. This module provides for flexible logging of client requests. Logs are written in a customizable format, and may be written directly to a file, or to
mysql: –i-am-a-dummy
This option prevents MySQL from performing update operations unless a key constraint in the WHERE clause and / or a LIMIT clause are provided. mysql –i-am-a-dummy -uroot test For beginners, a useful startup option is –safe-updates (or –i-am-a-dummy, which has
Scheduling tasks with cron
Cron is a daemon used for scheduling tasks to be executed at a certain time. Cron is driven by a crontab, a configuration file that specifies shell commands to run periodically on a given schedule. Each user has a
Hello world!
First article! Definitely must be a “Hello World” examples article. A “Hello World” program is a computer program which prints out “Hello, world!” on a display device. It is used in many introductory tutorials for teaching a programming language. It