What Exactly is an Arduino? 3rd post

The Arduino can also be extended with the use of shields, which are circuit boards containing otherdevices (e.g. GPS receivers, LCD Displays, Ethernet modules, etc.) that you can simply connect to the topof your Arduino to get extra functionality. Shields also extend the pins to the top of its own circuit boardso you still have access to all of them. You don’t have to use a shield if you don’t want to; you can make

the exact same circuitry using a breadboard, Stripboard, Veroboard, or by making your own PCB. Mostof the projects in this book are made using circuits on a breadboard.

There are many different variants of the Arduino. The latest version is the Arduino Uno. Theprevious version, the very popular Duemilanove (Italian for 2009), is the board you will most likely seebeing used in the vast majority of Arduino projects across the Internet. You can also get Mini, Nano, andBluetooth variations of the Arduino. Another new addition to the product line is the Arduino Mega 2560;

it offers increased memory and number of I/O pins. The new boards use a new bootloader calledOptiboot, which frees up another 1.5k of flash memory and enables faster boot up.Probably the most versatile Arduino, and hence the reason it is the most popular, is the Uno, or itspredecessor, the Duemilanove. This is because it uses a standard 28-pin chip attached to an IC(Integrated Circuit) socket. The beauty of this system is that if you make something with an Arduino andthen want to turn it into something permanent, instead of using a relatively expensive Arduino board,

you can simply pop the chip out of the board and place it into your own circuit board in your customdevice. By doing so, you have made a custom embedded device, which is really cool.Then, for a couple of quid or bucks, you can replace the AVR chip in your Arduino with a new one.Note that the chip must be pre-programmed with the Arduino Bootloader (software programmed ontochip to enable it to be used with the Arduino IDE), but you can either purchase an AVR Programmerto burn the bootloader yourself or you can buy a chip ready programmed; most of the Arduino partssuppliers provide these. It is also possible to program a chip using a second Arduino; instructions are

available online for this.