diff --git a/tests/components/knx/test_sensor.py b/tests/components/knx/test_sensor.py
new file mode 100644
index 00000000000..16ea5e8d385
--- /dev/null
+++ b/tests/components/knx/test_sensor.py
@@ -0,0 +1,95 @@
+"""Test KNX sensor."""
+from homeassistant.components.knx.const import CONF_STATE_ADDRESS, CONF_SYNC_STATE
+from homeassistant.components.knx.schema import SensorSchema
+from homeassistant.const import CONF_NAME, CONF_TYPE, STATE_UNKNOWN
+from homeassistant.core import HomeAssistant
+
+from .conftest import KNXTestKit
+
+from tests.common import async_capture_events
+
+
+async def test_sensor(hass: HomeAssistant, knx: KNXTestKit):
+    """Test simple KNX sensor."""
+
+    await knx.setup_integration(
+        {
+            SensorSchema.PLATFORM_NAME: {
+                CONF_NAME: "test",
+                CONF_STATE_ADDRESS: "1/1/1",
+                CONF_TYPE: "current",  # 2 byte unsigned int
+            }
+        }
+    )
+    assert len(hass.states.async_all()) == 1
+    state = hass.states.get("sensor.test")
+    assert state.state is STATE_UNKNOWN
+
+    # StateUpdater initialize state
+    await knx.assert_read("1/1/1")
+    await knx.receive_response("1/1/1", (0, 40))
+    state = hass.states.get("sensor.test")
+    assert state.state == "40"
+
+    # update from KNX
+    await knx.receive_write("1/1/1", (0x03, 0xE8))
+    state = hass.states.get("sensor.test")
+    assert state.state == "1000"
+
+    # don't answer to GroupValueRead requests
+    await knx.receive_read("1/1/1")
+    await knx.assert_no_telegram()
+
+
+async def test_always_callback(hass: HomeAssistant, knx: KNXTestKit):
+    """Test KNX sensor with always_callback."""
+
+    events = async_capture_events(hass, "state_changed")
+    await knx.setup_integration(
+        {
+            SensorSchema.PLATFORM_NAME: [
+                {
+                    CONF_NAME: "test_normal",
+                    CONF_STATE_ADDRESS: "1/1/1",
+                    CONF_SYNC_STATE: False,
+                    CONF_TYPE: "percentU8",
+                },
+                {
+                    CONF_NAME: "test_always",
+                    CONF_STATE_ADDRESS: "2/2/2",
+                    SensorSchema.CONF_ALWAYS_CALLBACK: True,
+                    CONF_SYNC_STATE: False,
+                    CONF_TYPE: "percentU8",
+                },
+            ]
+        }
+    )
+    assert len(hass.states.async_all()) == 2
+    # state changes form None to "unknown"
+    assert len(events) == 2
+
+    # receive initial telegram
+    await knx.receive_write("1/1/1", (0x42,))
+    await knx.receive_write("2/2/2", (0x42,))
+    await hass.async_block_till_done()
+    assert len(events) == 4
+
+    # receive second telegram with identical payload
+    # always_callback shall force state_changed event
+    await knx.receive_write("1/1/1", (0x42,))
+    await knx.receive_write("2/2/2", (0x42,))
+    await hass.async_block_till_done()
+    assert len(events) == 5
+
+    # receive telegram with different payload
+    await knx.receive_write("1/1/1", (0xFA,))
+    await knx.receive_write("2/2/2", (0xFA,))
+    await hass.async_block_till_done()
+    assert len(events) == 7
+
+    # receive telegram with second payload again
+    # always_callback shall force state_changed event
+    await knx.receive_write("1/1/1", (0xFA,))
+    await knx.receive_write("2/2/2", (0xFA,))
+    await hass.async_block_till_done()
+    assert len(events) == 8