This module is based upon the Allegro A4988 stepper motor driver and is ideal for use in 3D printer, CNC, and other applications where precise control of a stepper motor is required. Its pinnout is compatible with the StepStick design. This module can be used on its own (controlled by a microcontroller), or used with a RepRap compatible RAMPS shields such as our item number HC3DPR0002.
The A4988 is a complete microstepping motor driver with built-in translator for easy operation. It is designed to operate
bipolar stepper motors in full-, half-, quarter-, eighth-, and sixteenth-step modes, with an output drive capacity of up to
35 V and ±1 A (Although the A4988 device is rated to 2A, this module has a maximum current of 1A). The A4988 includes a fixed off-time current regulator which has the ability to operate in Slow or Mixed decay modes. The translator is the key to the easy implementation of the A4988. Simply inputting one pulse on the STEP input drives
the motor one microstep. There are no phase sequence tables, high frequency control lines, or complex interfaces to program. The A4988 interface is an ideal fit for applications where a complex microprocessor is unavailable or is overburdened. During stepping operation, the chopping control in the A4988 automatically selects the current decay mode, Slow or Mixed. In Mixed decay mode, the device is set initially to a fast decay for a proportion of the fixed off-time, then to a slow decay for the remainder of the off-time. Mixed decay current control results in reduced audible motor noise, increased step accuracy, and reduced power dissipation.