Getting to know the Arduino Uno Board
In a previous post, Josh thoroughly described the useful and interactive pieces of the Arduino Uno board. This article intends to describe physical components on the board that are not the pins and headers, in order to give new users a "tour" of the Arduino. Many of my explanations will describe components in relation to the locations of other parts. For our purposes, we will orient the Arduino Uno with its power and USB ports on the top and the components out in front of us. And generally, we will travel counter clockwise around the board. First up, the AT328Mega Microcontroller.
|Picture of the Arduino Uno, oriented with the USB and Power ports on the top|
AT328The physically largest component on the Uno board is the AT328Mega Microcontroller, which is laid out in a vertical column just to the right of the analog pins, extending from the bottom portion to about two-thirds of the way up the board. This microcontroller is the essentially the "brains" of the Arduino, it is a computer chip that contains the CPU, a small amount of memory, and inputs/output capabilities that are realized by Arduino's analog and digital pins. More information about microcontrollers in general (what they do and how they work) can be found all over the internet, though I quite like Instructables.com's overview which can be found here.
The ICSPsDirectly to the right of the AT328, at the very bottom of the board, there is a little 3x2 grid of pins (sort of resembling a bed of needles, or a Braille cel) that poke straight up. The ICSP is used to install a bootloader on your Arduino if it is no longer functioning. As beginners, we won't interact with ICSP but it is a good landmark to orient yourself to the board. More info about Arduino Bootloaders is here.
Moving to the right around the perimeter of the board, you will next encounter the digital pins, which are in a column formation along the right edge. Again, Josh explained these in great detail here. Just to the left of the very top two digital pins is a second ICSP (3x2 grid of pins), oriented perpendicular to the ICSP on the bottom of the board.