MEGA2560 2012 R3 edition is the latest version of the MEGA series controller, and the differences between the 2011 versions:
1 ATMEGA16U2 is used to replace the 2011 version of the ATMEGA8U2, the ISP FLASH capacity doubled, to more powerful function expansion, development needs. ATMEGA16U2 in addition to the traditional USB to serial port function, still can let user programming to define other functions, such as the USB port configuration into a mouse, keyboard, joystick, camera and so on,
2 external interface increased SDA, SCL in 2011 versions (position on the left-hand side of the AREF). The IOREF interface can be provided to Shield a voltage reference. And in order to compatibility series products will consider IOREF left aside for a port.
3. RESET circuit is more improved than version 2011. To prevent accidental reset RESET, RESET circuit is more stable.
Arduino Mega is a ATmega2560 as the core microcontroller development board, itself has 54 groups of digital I/O input/output end (14 of which group do PWM output), 16 groups of simulation than input, 4 groups of UART (hardware serial ports), using 16 MHz crystal oscillator. As with bootloader, it can directly through USB to download the program without other external programmer. The power supply part can be selected by USB power supply, or use AC-to-DC adapter as the external power supply and battery.
Because of the open source code, and using the concept of Java (cross platform) of the C language development environment, make peripheral module and application of rapid growth. The main reason and attract Artist using can be quickly using language and Flash or Processing... Software, communication, make the multimedia interactive works. development of IDE interface based on the principle of open source code, can let you use the free download in the monograph, the school teaching, motor control, interactive works etc..
Power supply design
Power supply system of Mega have two kinds of choices, USB direct power supply or external power supply. Automatic switching will power supply. The external power supply can choose AC-to-DC adapter or battery, the limit voltage range control board for the 6V~12V, but if the supply voltage is less than 6V, I/O port may not be provided to the 5V voltage, so there will be unstable; if the supply voltage is greater than 12V, voltage stabilizing device will likely overheat protection, are more likely to damage MEGA. The power supply operation for 6.5~12V, recommend the power for the 7V or 12V.