Here is a standalone stepper motor driver that is rated at 2.5 peak amps per phase. The driver will also accept a range of 8.2 to 45 volts and can be microstepped up to 1/32 (the step modes are: full, 1/2, 1/4, 1/8, 1/6 and 1/32).
This is an exceptionally smooth 2.5 amp standalone stepping motor driver that can be microstepped up to a respectably high 1/32. The driver is also very easy to configure with only one trimmer to set the amount of current you will allow the motor to draw. The driver chip has all kinds of built-in protection including protection for heat and over current, so you can use this driver with piece of mind.
The EN is an enable pin and will enable the chip at a low state (0 volts or GND). Left unconnected is the same as enabling the chip, so if you intend to keep the chip on when the system is powered, keep this terminal unconnected. The CW is direction where the motor will turn in one direction when high and the other direction when low. This terminal is generally connected to the breakout board on the terminal/pin you assigned in software for direction. In software, just change from active high to active low (or invert if using linuxcnc) to reverse the directions. The CP is the step pulse terminal and this will step the motor (turn the motor single steps). The steps will be equal to the full step multiplied by the microsteps that you set the dip switch. There is a ground terminal next to the 12-24v terminal and that is a common ground for high voltage and signal voltage.
If you are needing more detailed information, please refer to the driver IC DRV8825 datasheet.