Add MX-T40 BLE desktop controller and protocol documentation

tests/test_status.py

@@ -0,0 +1,21 @@
+"""Decode actual status payloads without constructing a Tk window."""
+
+import unittest
+
+from controller.messages import describe_reply
+
+
+class StatusTests(unittest.TestCase):
+    def test_captured_standard_eq(self):
+        self.assertEqual(describe_reply(bytes.fromhex("41 03 02 00")), "EQ: Standard")
+
+    def test_captured_volume_mute_and_lighting(self):
+        for raw, expected in [
+            ("41 01 0b 00", "Volume: 11"),
+            ("41 01 0c 00", "Volume: 12"),
+            ("41 07 01 00", "Mute: On"),
+            ("41 07 02 00", "Mute: Off"),
+            ("51 03 03", "Lighting: Dance"),
+        ]:
+            with self.subTest(raw=raw):
+                self.assertEqual(describe_reply(bytes.fromhex(raw)), expected)