[companion] Implement switching to device and connecting

companion/app.py

+import logging
+
 from kivy.app import App
+from kivy.logger import Logger
+from kivy.uix.boxlayout import BoxLayout
 
+from device import DeviceWidget
 from device_list import DeviceListWidget
 
 
+class InterfaceManager(BoxLayout):
+    def show_device_list(self):
+        self.clear_widgets()
+        self.add_widget(DeviceListWidget())
+
+    def show_device(self, address):
+        self.clear_widgets()
+        self.add_widget(DeviceWidget(address))
+
+
 class MynitCompanionApp(App):
     def build(self):
-        self.widget = DeviceListWidget()
+        Logger.setLevel(logging.DEBUG)
+        self.widget = InterfaceManager()
+        self.widget.show_device_list()
         return self.widget

companion/device.py

+import asyncio
+
+from kivy.logger import Logger
+from kivy.uix.widget import Widget
+
+from bleak import BleakClient
+
+
+UART_SERVICE_UUID = "6e400001-b5a3-f393-e0a9-e50e24dcca9e"
+UART_SERVICE_TX_UUID = "6e400002-b5a3-f393-e0a9-e50e24dcca9e"
+UART_SERVICE_RX_UUID = "6e400003-b5a3-f393-e0a9-e50e24dcca9e"
+
+
+class DeviceWidget(Widget):
+    def __init__(self, address, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+
+        self._task_queue = set()
+
+        self._client = BleakClient(address)
+        Logger.info(f"Connecting to device: {address}")
+        task = asyncio.create_task(self._client.connect())
+        self._task_queue.add(task)
+        task.add_done_callback(self._connected)
+
+    def _connected(self, task):
+        Logger.info("Connected")
+        self._task_queue.discard(task)
+
+        Logger.info("Starting notifications for UART")
+        task = asyncio.create_task(self._client.start_notify(UART_SERVICE_RX_UUID, self._handle_rx))
+        self._task_queue.add(task)
+        task.add_done_callback(self._reading)
+
+    def _reading(self, task):
+        Logger.debug("Reading UART data now")
+        self._task_queue.discard(task)
+        self.send_line('print("Hallo Welt")')
+
+    def _handle_rx(self, count, data):
+        Logger.debug(f"Received: {data}")
+
+    def send_line(self, data):
+        if not data.endswith("\r\n"):
+            data += "\r\n"
+        data = data.encode()
+
+        Logger.debug(f"Sending: {data}")
+        task = asyncio.create_task(self._client.write_gatt_char(UART_SERVICE_TX_UUID, data))
+        self._task_queue.add(task)
+        task.add_done_callback(self._task_queue.discard)

companion/device_list.py

 import asyncio
 
+from kivy.app import App
 from kivy.logger import Logger
 from kivy.uix.button import Button
 from kivy.uix.widget import Widget
@@ -33,11 +34,12 @@ class DeviceListWidget(Widget):
 
     def do_connect(self, address):
         Logger.info(f"Connecting to device: {address}")
+        App.get_running_app().root.show_device(address)
 
     def _new_device(self, device, advertisement):
         Logger.info(f"New device discovered: {device}")
         # FIXME Remove this filter
-        if device.name != "FroSCon-Wetter":
+        if device.name != "FrOSCon-Wetter":
             return
         widget = self
         btn = Button(text=device.name, on_press=lambda self: widget.do_connect(device.address))