User friendly USB programmable Arduino Microcontroller
Open Source design based on the larger ATmega2560
54 digital I/O Pins and 16 analog I/O Pins
256 KB of Flash Memory, 8 KB of SRAM, and 4kB of EEPROM
Clock Speed: 16 MHz
The Arduino Mega 2560 is a microcontroller board based on the ATmega2560. It has 54 digital input/output pins (of which 14 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. It contains everything needed to support the microcontroller; simply connect it to a computer with a USB cable or power it with a AC-to-DC adapter or battery to get started. The Mega is compatible with most shields designed for the Arduino Uno, Duemilanove, or Diecimila.
The Arduino Mega can be powered via the USB Connection or with an external power supply. The Mega2560 differs from all preceding boards in that it does not use the FTDI USB-to-serial driver chip. Instead, it features the Atmega8U2 programmed as a USB-to-serial converter.
Each of the 54 digital pins on the Mega can be used as an input or output, using pinMode(), digitalWrite(), and digitalRead() functions. It also has 16 analog inputs, each of which provide 10 bits of resolution (i.e. 1024 different values).
The Arduino Mega2560 has a number of facilities for communicating with a computer, another Arduino, or other microcontrollers. The ATmega2560 provides four hardware UARTs for TTL (5V) serial communication. An ATmega8U2 on the board channels one of these over USB and provides a virtual com port to software on the computer. Furthermore, it supports I2C (TWI) and SPI communication. The Arduino software includes a Wire library to simplify use of the I2C bus; see the documentation on the Wiring website for details. For SPI communication, use the SPI library.
The Arduino Mega2560 can be programmed with the free and open source Arduino IDE hrough a USB connection without needing any extra hardware thanks to its preburnt bootloader. You can also bypass the bootloader and program the microcontroller through the ICSP header.