Arduino Uno Quick Start Manual page 27

comes with the big standard-B plug, while other boards, such as the Arduino
Leonardo or the Arduino Due, have the small micro-B plugs.
You can use the USB connection for various purposes:
• Upload new software to the board. (You ll see how to do this in
and Uploading Programs, on page
• Communicate with the Arduino board and your computer. (You ll learn
that in Using Serial Ports, on page
• Supply the Arduino board with power.
As an electronic device, the Arduino needs power. One way to power it is to
connect it to a computer s USB port, but that isn t a good solution in some
cases. Some projects don t necessarily need a computer, and it would be
overkill to use a whole computer just to power the Arduino. Also, the USB
port delivers only 5 volts, and sometimes you need more.
In these situations, the best solu-
tion usually is an AC adapter
supplying 9 volts. (The recommend-
ed range is 7V to 12V.)
an adapter with a 2.1mm barrel
tip and a positive center. (You
don t need to understand what
that means; just ask for it in your
local electronics store.) Plug it into
the Arduino s power jack, and it
will start immediately, even if it
isn t connected to a computer. By the way, even if you connect the Arduino
to a USB port, it will use the external power supply if available.
Please note that older versions of the Arduino board (Arduino NG and Diecim-
ila) don t switch automatically between an external power supply and a USB
supply. They come with a power selection jumper labeled PWR_SEL, and you
manually have to set it to EXT or USB, respectively. (See
Arduinos have a power source selection jumper, on page
Now you know two ways to supply the Arduino with power. But the Arduino
isn t greedy and happily shares its power with other devices. At the bottom
of the board shown in
7. http://www.arduino.cc/playground/Learning/WhatAdapter
19.)
28.)
7
You need
Figure 1 A typical AC adapter.
Exploring the Arduino Board, on page
www.it-ebooks.info
Exploring the Arduino Board
Compiling
Figure 2, Older
8.)
6, you can see
7
report erratum discuss