diff --git a/test/test_RelativeEncoders/test_RelativeEncoders.cpp b/test/test_RelativeEncoders/test_RelativeEncoders.cpp
new file mode 100644
index 00000000..5a196e26
--- /dev/null
+++ b/test/test_RelativeEncoders/test_RelativeEncoders.cpp
@@ -0,0 +1,180 @@
+/* MIT License
+ *
+ * Copyright (c) 2023 Andreas Merkle <web@blue-andi.de>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+/**
+ * @author  Andreas Merkle <web@blue-andi.de>
+ * @brief   This module contains the program entry point for the tests.
+ */
+
+/******************************************************************************
+ * Compile Switches
+ *****************************************************************************/
+
+/******************************************************************************
+ * Includes
+ *****************************************************************************/
+
+#include <Arduino.h>
+#include <unity.h>
+#include <RelativeEncoders.h>
+
+/******************************************************************************
+ * Compiler Switches
+ *****************************************************************************/
+
+/******************************************************************************
+ * Macros
+ *****************************************************************************/
+
+/******************************************************************************
+ * Types and classes
+ *****************************************************************************/
+
+typedef struct
+{
+    int16_t encoderStepsLeft;
+    int16_t encoderStepsRight;
+    bool    isTest;
+    int16_t expectedDiffLeft;
+    int16_t expectedDiffRight;
+
+} Elem;
+
+/******************************************************************************
+ * Prototypes
+ *****************************************************************************/
+
+static void testRelativeEncoders();
+
+/******************************************************************************
+ * Local Variables
+ *****************************************************************************/
+
+/******************************************************************************
+ * Public Methods
+ *****************************************************************************/
+
+/******************************************************************************
+ * Protected Methods
+ *****************************************************************************/
+
+/******************************************************************************
+ * Private Methods
+ *****************************************************************************/
+
+/******************************************************************************
+ * External Functions
+ *****************************************************************************/
+
+/**
+ * Program setup routine, which is called once at startup.
+ */
+void setup()
+{
+#ifndef TARGET_NATIVE
+    /* https://docs.platformio.org/en/latest/plus/unit-testing.html#demo */
+    delay(2000);
+#endif /* Not defined TARGET_NATIVE */
+}
+
+/**
+ * Main entry point.
+ */
+void loop()
+{
+    UNITY_BEGIN();
+
+    RUN_TEST(testRelativeEncoders);
+
+    UNITY_END();
+
+#ifndef TARGET_NATIVE
+    /* Don't exit on the robot to avoid a endless test loop.
+     * If the test runs on the pc, it must exit.
+     */
+    for (;;)
+    {
+    }
+#endif /* Not defined TARGET_NATIVE */
+}
+
+/**
+ * Initialize the test setup.
+ */
+extern void setUp(void)
+{
+    /* Not used. */
+}
+
+/**
+ * Clean up test setup.
+ */
+extern void tearDown(void)
+{
+    /* Not used. */
+}
+
+/******************************************************************************
+ * Local Functions
+ *****************************************************************************/
+
+/**
+ * Test the relative encoders unit.
+ */
+static void testRelativeEncoders()
+{
+    IEncoders&          absEncoders     = Board::getInstance().getEncoders();
+    IEncodersTest&      absEncodersTest = Board::getInstance().getEncodersTest();
+    RelativeEncoders    relEncoders(absEncoders);
+    Elem                testVector[]    =
+    {
+        { 0,            0,          true,   0,      0   },
+        { 10,           10,         true,   10,     10  },
+        { -10,          -10,        true,   -10,    -10 },
+        { INT16_MAX,    INT16_MAX,  false,  0,      0   }, /* Preparation for wrap-around */
+        { INT16_MIN,    INT16_MIN,  true,   1,      1   },
+        { INT16_MIN,    INT16_MIN,  false,  0,      0   }, /* Preparation for wrap-around */
+        { INT16_MAX,    INT16_MAX,  true,   -1,     -1  }
+    };
+    uint8_t             idx             = 0;
+
+    idx = 0;
+    while ((sizeof(testVector) / sizeof(testVector[0])) > idx)
+    {
+        absEncodersTest.setCountsLeft(testVector[idx].encoderStepsLeft);
+        absEncodersTest.setCountsRight(testVector[idx].encoderStepsRight);
+        
+        if (false == testVector[idx].isTest)
+        {
+            relEncoders.clearLeft();
+            relEncoders.clearRight();
+        }
+        else
+        {
+            TEST_ASSERT_EQUAL_INT16(testVector[idx].expectedDiffLeft, relEncoders.getCountsLeft());
+            TEST_ASSERT_EQUAL_INT16(testVector[idx].expectedDiffRight, relEncoders.getCountsRight());
+        }
+
+        ++idx;
+    }
+}