The MEGA2560 2012 R3 version is a new version of the MEGA series controller. The differences from the 2011 version are as follows:
The ATMEGA16U2 chip replaces the ATMEGA8U2 of the 2011 version, and the ISPFLASH capacity is doubled, facilitating more powerful function expansion and development needs. In addition to providing the traditional USB-to-serial port function, the ATMEGA16U2 also allows users to program and define other functions by themselves. For example, the USB port can be configured as a mouse, keyboard, game joystick, camera, etc. Of course, the specific implementation plans for these applications are yet to be announced by the Arduino team.
The external interfaces have added SDA and SCL (located on the left side of AREF) on the basis of the 2011 version. The IOREF interface can provide a voltage reference for the Shield. And a port is reserved on the left side of IOREF for the compatibility of future series products.
The RESET circuit has been improved compared with the 2011 version. It prevents unexpected RESET, and the RESET circuit is more stable.
Mega Introduction: Mega is a microcontroller development board with ATmega2560 as the core. It has 54 sets of digital I/O input/output terminals (14 of which can be used for PWM output), 16 sets of analog input terminals, 4 sets of UART (hardware serial ports), and uses a 16 MHz crystal oscillator. Because it has a bootloader, programs can be directly downloaded via USB without going through other external programmers. For the power supply part, you can choose to be directly powered by USB or use an AC-to-DC adapter and a battery as the external power supply.