O'Reilly Webcast: First Steps with Arduino

In this webcast, Make Editor Brian Jepson introduces the basics of Arduino, the open source electronics prototyping platform. You'll learn what Arduino is, where to get one, and how to connect electronic components to it. You'll also learn how to write simple programs for Arduino. When you're done, you'll be ready to learn more, make more, and have fun prototyping. The last half hour of the recording is open chat following the webcast.

DIY Security System

Security system sensors such as motion detectors, reed switches, pressure mats, glass-break detectors, infra-red beams, and conductive film can be very handy for all sorts of things including home automation systems, interactive art installations - and sometimes even security systems! Almost all security system sensors provide a simple switched output that changes state based on whether the sensor has been tripped or not, which means that when connected up in a circuit they behave just like a switch that is activated automatically. That makes them extremely easy to connect to an Arduino to read their status.

Read more at http://www.practicalarduino.com/projects/security-sensors

pH meter using an Arduino board

Carlos from Brazil has designed a pH meter using the Arduino. Although not available for sale yet (unless someone can help him get a full version of Eagle), all the code and associated files are available for download.

pHduino is a open hardware and open software for pH measuments using a glass electrode sensor for hydrogen ion and a Arduino board.

This pHmeter can be powered by a power supply and display the data using a LCD. Also, you can control it and power it up by USB port. The offset and slope can be adjust manually by potentiometers or by an auto calibration code (not implemented, yet). There is a temperature sensor for temperature compensation.

Model RailRoading with the Arduino

There's a number of good references on the net where folks are using the Arduino to control various aspects of their model railroad layouts. Here's a number of interesting projects:

http://modelrail.otenko.com/category/arduino

http://www.oscale.net/en/arduino

http://trackhacker.com/archives/tag/arduino