Add constructor for injecting devices in BasicChopperController

This is useful for cases where the pins may be active low, instead of active high.

Author: ketan

diozero-core/src/main/java/com/diozero/devices/sandpit/motor/ChopperStepperController.java

@@ -36,6 +36,8 @@
 import com.diozero.api.RuntimeIOException;
 import com.diozero.devices.sandpit.motor.StepperMotorInterface.Direction;
 
+import java.util.Objects;
+
 /**
  * A basic device for a stepper driven by a "chopper" driver: uses 3 GPIO pins (enable, direction, frequency) to
  * control a motor.
@@ -109,6 +111,21 @@ class BasicChopperController implements ChopperStepperController {
         private final DigitalOutputDevice directionSet;
         private final PwmOutputDevice stepControl;
 
+        /**
+         * Constructor that allows injecting the devices directly.
+         *
+         * @param enableDevice the device responsible to enable/disable the driver
+         * @param directionSet the device responsible to set the direction of rotation
+         * @param stepControl  the device responsible to control the stepping frequency and whether stepping or not
+         * @implNote The provided devices will be closed when this controller is closed.
+         */
+        public BasicChopperController(DigitalOutputDevice enableDevice, DigitalOutputDevice directionSet,
+                                      PwmOutputDevice stepControl) {
+            this.enableDevice = Objects.requireNonNull(enableDevice, "enableDevice must not be null");
+            this.directionSet = Objects.requireNonNull(directionSet, "directionSet must not be null");
+            this.stepControl = Objects.requireNonNull(stepControl, "stepControl must not be null");
+        }
+
         /**
          * Basic constructor for this type of driver.
          *
@@ -117,9 +134,9 @@ class BasicChopperController implements ChopperStepperController {
          * @param stepPin      controls the <i>frequency</i> of the motor and whether stepping or not
          */
         public BasicChopperController(int enablePin, int directionPin, int stepPin) {
-            enableDevice = new DigitalOutputDevice(enablePin, true, false);
-            directionSet = new DigitalOutputDevice(directionPin, true, false);
-            stepControl = new PwmOutputDevice(stepPin);
+            this(new DigitalOutputDevice(enablePin, true, false),
+                 new DigitalOutputDevice(directionPin, true, false),
+                 new PwmOutputDevice(stepPin));
         }
 
         @Override