The DRV8825 is a Motor Driver with two H-bridge drivers and a microstepping indexer. The driver has a maximum output capacity of 45 V and ± 2.5 A. It can operate bipolar stepper motors in full, 1/2, 1/4, 1/8, 1/16 and 1/32-step modes. This driver module is generally used in Robotics, ATMs and Gaming Machines.
The Arduino Nano is a small, complete, and breadboard-friendly board based on the ATmega328 (Arduino Nano 3.x). It has more or less the same functionality of the Arduino Duemilanove, but in a different package. It lacks only a DC power jack, and works with a Mini-B USB cable instead of a standard one.
The Arduino Due is a microcontroller board based on the Atmel SAM3X8E ARM Cortex-M3 CPU. It is the first Arduino board based on a 32-bit ARM core microcontroller. It has 54 digital input/output pins (of which 12 can be used as PWM outputs), 12 analog inputs, 4 UARTs (hardware serial ports), a 84 MHz clock, an USB OTG capable connection, 2 DAC (digital to analog), 2 TWI, a power jack, an SPI header, a JTAG header, a reset button and an erase button.