Keyestudio Mega (core to ATmega2560) is a development board (used with16MHz crystal oscillator ) of microcontroller. There are 54 I/O (input/output ) digital interfaces (of which 14 are PWM outputs), 16 analo g inputs and 4 UART (hardwareserial ports). With its bootloader, program can be downloaded directly with USB and you don’t need to use other external programmer. It can be driven directly by USB, or AC-to-DC adapter and battery.