Getting Acquainted With Arduino
Many of you must be reading this after referring other websites but still I expect you to go through this "story" as if you are hearing it for the first time. Please be patient till then :). Also suggestions are welcome if you think something is not correct.
Arduino is a tool that allows you to make projects with simple coding that
would else require a complex programming and circuitry. To start with imagine
arduino as a box that has some inputs and some outputs. What arduino does is it
fetches inputs, manipulates them and gives outputs according to the code that
it has. Thats arduino in a nutshell. We will get into the details after
checking out its various parts (I prefer using Arduino UNO but little things
change with different models) :-
1. USB Plug:- This port is used for uploading programs or commonly called
"Sketches" on your Arduino. This can also be used for powering
Arduino from your PC.
2. Digital I/O pins: Pin 2-13 as labelled in the picture are used for
taking digital inputs(0s and 1s or to be practical 0 volts or 5 volts) and for
giving digital outputs ( Though Arduino comes with a function to mimic analog
outputs that is almost continuous voltages from 0 to 5 volts).
3.Reset Button:- As the name suggests this button when pressed forces the
arduino board to restart itself resetting the program and memory content of
variables (we'll discuss all about it :P).
4.Serial Programmer:- These pins allows arduino to "communicate"
with your PC. For many basic applications you won't need them.
5.ATmega328 Microcontroller:- This is the "heart and brain" of
the Arduino. All the operations, decisions and manipulations are done in this
IC. It is a single package microprocessor with Memory for the program
instructions and data in it along with other resources like input output memory
blocks, timers etc. To conclude it is a tiny computer.
6.Analog in pins:- These pins are the most useful pins onboard on the
Arduino because these help us to communicate with analog sensors that sense
features of physical world( light, temperature , humidity etc.).
7. The Pins next to analog pins are the so called Power Pins. I will
describe each one of them below:-
a)Voltage in:-This pin can
be used to supply voltages ranging from 7-12 volts (to be on the safer side and
ensure that under no case you end up burning something) that is regulated to 5
volts and fed to the ATmega chip.
b)Ground Pins:- These
pins are connected to zero volt reference or the "Ground". Any
voltage read by or returned by Arduino is with respect to these pins.
c)5 Volt pin:- This pin
is 5 volts above the ground pins. These oins can source upto 200 mA of current but it is better to be
within 100 mA and not test the boards limits.
d)3.3 volt pin:- This pin
is 3.3 volt above the ground and is ideal for powering MOSFET based devices and
lightning LEDs.
e)The Reset Pin:- This
pin resets the arduino board whenever it sees a high or 5 volt above the
ground.
f)The power port:- This can be used for powering the board with unregulated dc voltage of 7- 12 volts.(Again little less than its tolerance to be safe).