Add MX-T40 BLE desktop controller and protocol documentation

controller/link.py

@@ -0,0 +1,55 @@
+"""Experimental RFCOMM/serial adapter for the shared Samsung session."""
+
+import queue
+import time
+
+from controller.session import Session
+from controller.transport import open_stream
+from controller.worker import ConnectionWorker
+
+
+class Link(ConnectionWorker):
+    def __init__(self, port, events, channel=1, prepare=False):
+        super().__init__(port, events)
+        self.channel = channel
+        self.prepare = prepare
+
+    def work(self):
+        self.events.put(("log", f"Opening {self.port} (direct RFCOMM uses channel {self.channel})"))
+
+        def report(text):
+            self.events.put(("status", text))
+            self.events.put(("log", text))
+
+        with open_stream(self.port, self.channel, self.prepare, report) as stream:
+            session = Session(strict_checksums=True)
+
+            def send(packet):
+                if stream.write(packet) != len(packet):
+                    raise OSError("Incomplete Bluetooth write")
+                self.events.put(("log", "TX " + packet.hex(" ")))
+
+            report("Bluetooth connected; waiting for speaker handshake…")
+            send(session.start())
+            deadline = time.monotonic() + 10
+            last_sent = time.monotonic()
+            while not self.stopped.is_set():
+                chunk = stream.read(1024)
+                if chunk:
+                    self.events.put(("log", "RX " + chunk.hex(" ")))
+                update = session.receive(chunk)
+                self.publish(update)
+                for packet in update.outgoing:
+                    send(packet)
+                    last_sent = time.monotonic()
+                if not session.ready and time.monotonic() > deadline:
+                    raise TimeoutError(
+                        "No completed speaker handshake. Close the phone app and check the TX/RX log."
+                    )
+                if session.ready and time.monotonic() - last_sent >= 0.1:
+                    try:
+                        payload = self.commands.get_nowait()
+                    except queue.Empty:
+                        continue
+                    send(session.command(payload))
+                    last_sent = time.monotonic()