DRV8825 - How it works
This is a DRV8825 Stepper motor board designed for precise control of stepper motors. This breakout board features the DRV8825 driver, which supports microstepping down to 1/32 of a regular step. This board also has overcurrent and overtemperature protection. A built-in potentiometer enables easy current regulation.
Datasheet
For an in-depth look at technical specifications, refer to the official DRV8825 Datasheet:
MAX7219 Datasheet
Detailed technical documentation for the DRV8825 driver
Stepper Motor Basics
A stepper motor is a type of motor that moves in discrete steps rather than continuous rotation like a DC motor. It does this by energizing different coils (or phases) in a sequence. There are two main types of stepper motors:
- Bipolar stepper motors have two coils and require H-bridge control to reverse the direction of current flow in each coil. This breakout board provides that control using four NPN transistors to switch the motor windings.
- Unipolar stepper motors have a center tap on each coil, allowing them to be driven more simply, though they are less efficient. This driver can also be used with unipolar stepper motors by only energizing one side of each coil at a time.
Driving the Stepper Motor
The DIR and STEP pins on the board serve as control pins. The DIR pin is used to set the rotation direction—LOW for clockwise and HIGH for counterclockwise. Each HIGH pulse sent to the STEP pin moves the motor one step. The output pins B2, B1, A1, and A2 control the flow of current from VIN through the motor winding to ground in sequential order, which allows the stepper motor to move step by step.