Basics of Arduino

The differences between Arduino UNO and Arduino Mega 2560 are as follow. The Arduino UNO is a microcontroller board based on the ATmega328 (datasheet). It has 14 digital input/output pins (of which 6 can be used as PWM outputs), 6 analog inputs, a 16 MHz ceramic resonator, a USB connection, a power jack, an ICSP header, and a reset button.   Arduino Uno The UNO differs from all preceding boards in that it does not use the FTDI USB-to-serial driver chip. Instead, it features the Atmega16U2 (Atmega8U2 up to version R2) programmed as a USB-to-serial converter.     Arduino Mega 2560 The Arduino Mega 2560 is a microcontroller board based on the ATmega2560 (datasheet). It has 54 digital input/output pins (of which 15 can be used as PWM outputs), 16 analog inputs, 4 UARTs (hardware serial ports), a 16 MHz crystal oscillator, a USB connection, a power jack, an ICSP header, and a reset button. The Mega is compatible with most shields designed for the Arduino Duemilanove or Diecimila.

Arduino is an electronics open source platform based on use hardware and software. It can be able to read inputs (light on sensor,figure on a burr-on, or send message) and turn it into an output (activating a motor, turning on LED, publishing something online).   First of all I'm introducing to Arduino Boards  1. ARDUINO UNO R3   ARDUINO UNO R3 based board( Micro-controller) . It has 20 digital input/output pin. Which 6 can be used as PWM ( Pulse Width Modulation ) outputs and 6 can be used as analog inputs.    Arduino Board The Main components of Arduino UNO board are as follows: USB connector Power port Micro-controller Analog input pins Digital pins Reset switch Crystal oscillator USB interface chip TX RX LED's