ARDUINO

Arduino

Arduino is a computer hardware and software company, project, and user community that designs and manufactures micro-controller kits for building digital devices and interactive objects that can sense and control objects in the physical world.

Arduino board designs use a variety of microprocessors and controllers. The boards are equipped with sets of digital and analog input/output (I/O) pins that may be interfaced to various expansion boards (shields) and other circuits. The boards feature serial communications interfaces, including Universal Serial Bus (USB) on some models, which are also used for loading programs from personal computers. The microcontrollers are typically programmed using a dialect of features from the programming languages C and C++. In addition to using traditional compiler toolchains, the Arduino project provides an integrated development environment (IDE) based on the Processing language project.

Hardware

Arduino is open-source hardware. This means that anyone is allowed to make Arduino-compatible boardc.
An Arduino board consists of an Atmel 8-, 16- or 32-bit AVR micro-controller (ATmega8, ATmega168, ATmega328, ATmega1280, ATmega2560). The boards use single-row pins or female headers that facilitate connections for programming and incorporation into other circuits. These may connect with add-on modules termed shields. Multiple, and possibly stacked shields may be individually addressable via an I²C serial bus. Most boards include a 5 V linear regulator and a 16 MHz crystal oscillator or ceramic resonator. Some designs, such as the LilyPad, run at 8 MHz and dispense with the onboard voltage regulator due to specific form-factor restrictions.
Arduino micro-controllers are pre -programmed with a boot loader that simplifies uploading of programs to the on-chip flash memory. The default bootloader of the Aduino UNO is the optiboot bootloader.^[12] Boards are loaded with program code via a serial connection to another computer. Some serial Arduino boards contain a level shifter circuit to convert between RS-232 logic levels and transistor–transistor logic (TTL) level signals. Current Arduino boards are programmed via Universal Serial Bus (USB), implemented using USB-to-serial adapter chips such as the FTDI FT232. Some boards, such as later-model Uno boards, substitute the FTDI chip with a separate AVR chip containing USB-to-serial firmware, which is reprogrammable via its own ICSP header. Other variants, such as the Arduino Mini and the unofficial Boarduino, use a detachable USB-to-serial adapter board or cable, Bluetooth or other methods, when used with traditional microcontroller tools instead of the Arduino IDE, standard AVR in-system programming (ISP) programming is used.
Shields
Arduino and Arduino-compatible boards use printed circuit expansion boards called shields, which plug into the normally supplied Arduino pin headers. Shields can provide motor controls for 3D printing and other applications, Global Positioning System (GPS), Ethernet, liquid crystal display (LCD), or breadboarding (prototyping).
Basically three shields are used –

·       USB Master Shield allows us to connect to Android devices over USB.

·       Motor Shield helps in driving the wheels of the robot.

·       Ethernet Shield allows us to turn our Arduino into a tiny web server.

Official boards of Arduino

• Arduino RS232
  (thru-hole parts)
• Arduino Diecimila
• Arduino Duemilanove
  (rev 2009b)
• Arduino Uno R2
• Arduino Uno SMD R3
• Arduino Leonardo
• Arduino Pro
  (No USB)
• Arduino Mega
• Arduino Nano
  (DIP-30 footprint)
• Arduino LilyPad 00
  (rev 2007) (No USB)
• Arduino Robot
• Arduino Esplora
• Arduino Ethernet
  (AVR + W5100)
• Arduino Yun
  (AVR + AR9331)
• Arduino Due
  (ARM Cortex-M3 core)