Block Diagram The security system comprises of an Arduino Uno microcontroller and a standard SIM900A based GSM/GPRS modem. The whole system can be powered from any 12VDC/2A power supply unit/battery.

The Arduino Wire library is a core aspect of Arduino's integrated development environment, or IDE, and is a must-have if you're using sensors or extra microcontrollers in your project. Like ...

Well tech tinkerer Joe Desbonnet has whipped up what he dubs "poor man's NFC" using an Arduino, some magnet wire, and any compass-equipped Android smartphone (which is almost all of them).