diff --git a/pi4micronaut-utils/src/test/java/com/opensourcewithslu/inputdevices/PhotoResistorHelperTest.java b/pi4micronaut-utils/src/test/java/com/opensourcewithslu/inputdevices/PhotoResistorHelperTest.java
new file mode 100644
index 00000000..69a78fe9
--- /dev/null
+++ b/pi4micronaut-utils/src/test/java/com/opensourcewithslu/inputdevices/PhotoResistorHelperTest.java
@@ -0,0 +1,142 @@
+package com.opensourcewithslu.inputdevices;
+import static org.junit.jupiter.api.Assertions.*;
+import static org.mockito.Mockito.*;
+
+import com.opensourcewithslu.mock.MockDigitalInput;
+import com.pi4j.io.gpio.digital.*;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import java.lang.reflect.Field;
+
+public class PhotoResistorHelperTest{
+    private MockDigitalInput mockDigitalInput;
+    private DigitalOutput mockDigitalOutput;
+    private PhotoResistorHelper photoResistorHelper;
+
+    @BeforeEach
+    public void setup(){
+        mockDigitalInput = new MockDigitalInput();
+        mockDigitalOutput = mock(DigitalOutput.class);
+        photoResistorHelper = new PhotoResistorHelper(mockDigitalInput,mockDigitalOutput);
+    }
+
+    @Test
+    public void testInitializationLogic() {
+        mockDigitalInput.SetState(DigitalState.LOW);
+        PhotoResistorHelper helperLow = new PhotoResistorHelper(mockDigitalInput, mockDigitalOutput);
+        assertFalse(helperLow.isDark);
+
+        mockDigitalInput.SetState(DigitalState.HIGH);
+        PhotoResistorHelper helperHigh = new PhotoResistorHelper(mockDigitalInput, mockDigitalOutput);
+        assertTrue(helperHigh.isDark);
+    }
+
+    @Test
+    public void testDarknessLevelCalculation() throws Exception {
+        PhotoResistorHelper helper = new PhotoResistorHelper(mockDigitalInput, mockDigitalOutput);
+
+        helper.setDarknessThreshold(50);
+
+        Field startTimeField = PhotoResistorHelper.class.getDeclaredField("startTime");
+        startTimeField.setAccessible(true);
+        startTimeField.setLong(helper, System.currentTimeMillis() - 100);
+
+        helper.updateDark();
+
+        Field endTimeField = PhotoResistorHelper.class.getDeclaredField("endTime");
+        endTimeField.setAccessible(true);
+        endTimeField.setLong(helper, System.currentTimeMillis());
+
+        Field darknessField = PhotoResistorHelper.class.getDeclaredField("darknessValue");
+        darknessField.setAccessible(true);
+        int darknessValue = (int) (endTimeField.getLong(helper) - startTimeField.getLong(helper));
+        darknessField.setInt(helper, darknessValue);
+
+        assertTrue(darknessValue > 0);
+
+        Field isDarkField = PhotoResistorHelper.class.getDeclaredField("isDark");
+        isDarkField.setAccessible(true);
+        isDarkField.setBoolean(helper, darknessValue > 50);
+
+        boolean isDark = isDarkField.getBoolean(helper);
+        assertTrue(isDark);
+    }
+
+    @Test
+    public void testGetDark() throws Exception {
+        PhotoResistorHelper helper = new PhotoResistorHelper(mockDigitalInput, mockDigitalOutput);
+
+        Field darknessField = PhotoResistorHelper.class.getDeclaredField("darknessValue");
+        darknessField.setAccessible(true);
+        darknessField.setInt(helper, 157);
+
+        assertEquals(157, helper.getDark());
+    }
+
+    @Test
+    public void testSetToLow() {
+        mockDigitalInput.SetState(DigitalState.HIGH);
+        PhotoResistorHelper helper = new PhotoResistorHelper(mockDigitalInput, mockDigitalOutput);
+
+        helper.setToLow();
+        verify(mockDigitalOutput).low();
+    }
+
+    @Test
+    public void testSetDarknessThreshold() throws Exception {
+        PhotoResistorHelper helper = new PhotoResistorHelper(mockDigitalInput, mockDigitalOutput);
+        helper.setDarknessThreshold(300);
+
+        Field thresholdField = PhotoResistorHelper.class.getDeclaredField("darknessThreshold");
+        thresholdField.setAccessible(true);
+        int actualThreshold = thresholdField.getInt(helper);
+
+        assertEquals(300, actualThreshold);
+    }
+
+    @Test
+    public void testEventListenerManagement() {
+        DigitalInput mockInput = mock(DigitalInput.class);
+        PhotoResistorHelper helper = new PhotoResistorHelper(mockInput, mockDigitalOutput);
+        DigitalStateChangeListener mockListener = mock(DigitalStateChangeListener.class);
+
+        helper.addEventListener(mockListener);
+        verify(mockInput, times(1)).addListener(mockListener);
+
+        helper.removeEventListener();
+        verify(mockInput, times(1)).removeListener(mockListener);
+    }
+
+    @Test
+    public void testEdgeCases() throws Exception {
+        PhotoResistorHelper helper = new PhotoResistorHelper(mockDigitalInput, mockDigitalOutput);
+
+        helper.removeEventListener();
+        helper.initialize();
+
+        long fakeStartTime = System.currentTimeMillis() - 600;
+        long fakeEndTime = System.currentTimeMillis();
+
+        Field startTimeField = PhotoResistorHelper.class.getDeclaredField("startTime");
+        startTimeField.setAccessible(true);
+        startTimeField.setLong(helper, fakeStartTime);
+
+        Field endTimeField = PhotoResistorHelper.class.getDeclaredField("endTime");
+        endTimeField.setAccessible(true);
+        endTimeField.setLong(helper, fakeEndTime);
+
+        Field darknessField = PhotoResistorHelper.class.getDeclaredField("darknessValue");
+        darknessField.setAccessible(true);
+        int expectedDarkness = (int) (fakeEndTime - fakeStartTime);
+        darknessField.setInt(helper, expectedDarkness);
+
+        assertEquals(expectedDarkness, helper.getDark());
+
+        assertDoesNotThrow(() -> {
+            helper.removeEventListener();
+            helper.removeEventListener();
+        });
+    }
+}