Tilt Switch implementation. Issue #40 (#232)

* tilt switch controller and helper

* added javadocs to helper

* fixed error in TouchSwitchHelper

* added comments to controller

components/src/main/java/com/opensourcewithslu/components/controllers/TiltSwitchController.java

@@ -0,0 +1,44 @@
+package com.opensourcewithslu.components.controllers;
+
+import com.opensourcewithslu.inputdevices.TiltSwitchHelper;
+import com.opensourcewithslu.outputdevices.LEDHelper;
+import com.pi4j.io.gpio.digital.DigitalInput;
+import com.pi4j.io.gpio.digital.DigitalOutput;
+import io.micronaut.http.annotation.Controller;
+import io.micronaut.http.annotation.Get;
+import jakarta.inject.Named;
+
+//tag::ex[]
+@Controller("/tiltSwitch")
+public class TiltSwitchController {
+
+    private final TiltSwitchHelper tiltSwitchHelper; // controls the tilt switch
+    private final LEDHelper ledHelper; // controls the LED
+
+    public TiltSwitchController(@Named("tilt-switch-input")DigitalInput tiltSwitch,
+                                @Named("led2")DigitalOutput led) {
+        this.tiltSwitchHelper = new TiltSwitchHelper(tiltSwitch);
+        this.ledHelper = new LEDHelper(led);
+    }
+
+    // The 'enable' method adds an event listener that listens for changes in the tilt switch
+    // If it is tilted, the LED turns on and off otherwise
+    @Get("/enable")
+    public void enableTiltSwitch() {
+        tiltSwitchHelper.addEventListener(e -> {
+            if (tiltSwitchHelper.isTilted) {
+                ledHelper.ledOn();
+            }
+            else {
+                ledHelper.ledOff();
+            }
+        });
+    }
+
+    // The disable method removes the event listener
+    @Get("/disable")
+    public void disableTiltSwitch() {
+        tiltSwitchHelper.removeEventListener();
+    }
+}
+//end::ex[]

components/src/main/resources/application.yml

@@ -101,6 +101,12 @@ pi4j:
       pull: PULL_DOWN
       debounce: 3000
       provider: pigpio-digital-input
+    tilt-switch-input:
+      name: Tilt Switch Input
+      address: 17
+      pull: PULL_DOWN
+      debounce: 5000
+      provider: pigpio-digital-input
   # end::digitalInput[]
 
   # tag::digitalOutput[]

pi4micronaut-utils/src/main/java/com/opensourcewithslu/inputdevices/TiltSwitchHelper.java

@@ -0,0 +1,66 @@
+package com.opensourcewithslu.inputdevices;
+
+import com.pi4j.io.gpio.digital.DigitalInput;
+import com.pi4j.io.gpio.digital.DigitalStateChangeListener;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Helper class to control a tilt switch using Digital Input.
+ * This class provides methods to initialize a tilt switch by adding or removing an event listener.
+ */
+public class TiltSwitchHelper {
+
+    private static final Logger log = LoggerFactory.getLogger(TiltSwitchHelper.class);
+    private final DigitalInput tiltSwitchInput;
+    private DigitalStateChangeListener tiltSwitchInputListener;
+    /**
+     * Boolean variable that is true if the tilt switch is being tilted and false otherwise.
+     */
+    public boolean isTilted;
+
+    /**
+     * TiltSwitchHelper constructor.
+     * @param tiltSwitchInput A Pi4J DigitalInput object.
+     */
+    public TiltSwitchHelper(DigitalInput tiltSwitchInput)
+    {
+        this.tiltSwitchInput = tiltSwitchInput;
+        this.isTilted = tiltSwitchInput.isHigh();
+
+        initialize();
+    }
+
+    /**
+     * Initializes the listener that keeps track of if the tilt switch is tilted.
+     * It is automatically called when the TiltSwitchHelper is instantiated.
+     */
+    private void initialize()
+    {
+        log.info("Initializing Tilt Switch");
+
+        tiltSwitchInputListener = e-> isTilted = tiltSwitchInput.isHigh();
+        tiltSwitchInput.addListener(tiltSwitchInputListener);
+    }
+
+    /**
+     * Adds an event listener to the tilt switch.
+     * @param function A Pi4J DigitalStateChangeListener object.
+     */
+    public void addEventListener(DigitalStateChangeListener function)
+    {
+        tiltSwitchInputListener = function;
+        tiltSwitchInput.addListener(tiltSwitchInputListener);
+    }
+
+    /**
+     * Removes the event listener from the tilt switch.
+     */
+    public void removeEventListener()
+    {
+        if (tiltSwitchInputListener != null) {
+            tiltSwitchInput.removeListener(tiltSwitchInputListener);
+            tiltSwitchInputListener = null;
+        }
+    }
+}

pi4micronaut-utils/src/main/java/com/opensourcewithslu/inputdevices/TouchSwitchHelper.java

@@ -10,7 +10,7 @@
  */
 public class TouchSwitchHelper {
 
-    private static final Logger log = LoggerFactory.getLogger(SlideSwitchHelper.class);
+    private static final Logger log = LoggerFactory.getLogger(TouchSwitchHelper.class);
 
     private final DigitalInput touchSwitchInput;
 
@@ -36,7 +36,7 @@ public TouchSwitchHelper(DigitalInput touchSwitchInput)
     /**
      * Initializes the listener that keeps track of if the touch switch has been touched or not. It is automatically called when the TouchSwitchHelper is instantiated.
      */
-    public void initialize()
+    private void initialize()
     {
         log.info("Initializing Touch Switch");