WIP: Add USB device support

TODO

Author: nkarstens

pybricksdev/cli/__init__.py

@@ -171,10 +171,11 @@ def add_parser(self, subparsers: argparse._SubParsersAction):
             )
 
     async def run(self, args: argparse.Namespace):
-        from ..ble import find_device
+        from ..ble import find_device as find_ble
         from ..connections.ev3dev import EV3Connection
         from ..connections.lego import REPLHub
         from ..connections.pybricks import PybricksHub
+        from usb.core import find as find_usb
 
         # Pick the right connection
         if args.conntype == "ssh":
@@ -188,11 +189,16 @@ async def run(self, args: argparse.Namespace):
         elif args.conntype == "ble":
             # It is a Pybricks Hub with BLE. Device name or address is given.
             print(f"Searching for {args.name or 'any hub with Pybricks service'}...")
-            device_or_address = await find_device(args.name)
+            device_or_address = await find_ble(args.name)
             hub = PybricksHub(device_or_address)
 
         elif args.conntype == "usb":
-            hub = REPLHub()
+            device_or_address = find_usb(idVendor=0x0483, idProduct=0x5740)
+
+            if device_or_address is not None and device_or_address.product == "Pybricks Hub":
+                hub = PybricksHub(device_or_address)
+            else:
+                hub = REPLHub()
         else:
             raise ValueError(f"Unknown connection type: {args.conntype}")
 

pybricksdev/connections/pybricks.py

@@ -17,7 +17,11 @@
 from reactivex.subject import BehaviorSubject, Subject
 from tqdm.auto import tqdm
 from tqdm.contrib.logging import logging_redirect_tqdm
-from typing import Callable
+from typing import Callable, Union
+from uuid import UUID
+from usb.core import Device as USBDevice
+from usb.control import get_descriptor
+from usb.util import *
 
 from ..ble.lwp3.bytecodes import HubKind
 from ..ble.nus import NUS_RX_UUID, NUS_TX_UUID
@@ -75,6 +79,79 @@ async def write_gatt_char(self, uuid: str, data, response: bool) -> None:
     async def start_notify(self, uuid: str, callback: Callable) -> None:
         return await self._client.start_notify(uuid, callback)
 
+class PybricksHubUSBClient:
+    _device: USBDevice
+    _disconnected_callback: Callable = None
+    _fw_version: str
+    _protocol_version: str
+    _hub_capabilities: bytearray
+
+    def __init__(self, device: USBDevice, disconnected_callback = None):
+        self._device = device
+        self._disconnected_callback = disconnected_callback
+
+    async def connect(self) -> bool:
+        self._device.set_configuration()
+
+        # Get length of BOS descriptor
+        bos_descriptor = get_descriptor(self._device, 5, 0x0F, 0)
+        (ofst, _, bos_len, _) = struct.unpack("<BBHB", bos_descriptor)
+
+        # Get full BOS descriptor
+        bos_descriptor = get_descriptor(self._device, bos_len, 0x0F, 0)
+
+        while ofst < bos_len:
+            (len, desc_type, cap_type) = struct.unpack_from("<BBB", bos_descriptor, offset=ofst)
+
+            if desc_type != 0x10:
+                logger.error("Expected Device Capability descriptor")
+                exit(1)
+
+            # Look for platform descriptors
+            if cap_type == 0x05:
+                uuid_bytes = bos_descriptor[ofst + 4 : ofst + 4 + 16]
+                uuid_str = str(UUID(bytes_le = bytes(uuid_bytes)))
+
+                if uuid_str == FW_REV_UUID:
+                    self._fw_version = bytearray(bos_descriptor[ofst + 20 : ofst + len - 1]) # Remove null-terminator
+                elif uuid_str == SW_REV_UUID:
+                    self._protocol_version = bytearray(bos_descriptor[ofst + 20 : ofst + len - 1]) # Remove null-terminator
+                elif uuid_str == PYBRICKS_HUB_CAPABILITIES_UUID:
+                    self._hub_capabilities = bytearray(bos_descriptor[ofst + 20 : ofst + len])
+
+            ofst += len
+
+        return True
+
+    async def disconnect(self) -> bool:
+        self._disconnected_callback()
+        return True
+
+    async def read_gatt_char(self, uuid: str) -> bytearray:
+        if uuid == FW_REV_UUID:
+            return self._fw_version
+        elif uuid == SW_REV_UUID:
+            return self._protocol_version
+        elif uuid == PYBRICKS_HUB_CAPABILITIES_UUID:
+            return self._hub_capabilities
+        elif uuid == PNP_ID_UUID:
+            return None
+
+    async def write_gatt_char(self, uuid: str, data, response: bool) -> None:
+        # Get output endpoint
+        cfg = self._device.get_active_configuration()
+        intf = cfg[(0,0)]
+        ep = find_descriptor(intf, custom_match = lambda e: endpoint_direction(e.bEndpointAddress) == ENDPOINT_OUT)
+
+        uuid_bytes = UUID(uuid).bytes_le
+        ep.write(uuid_bytes + data)
+
+        # TODO: Handle response
+
+    async def start_notify(self, uuid: str, callback: Callable) -> None:
+        # TODO
+        return
+
 class PybricksHub:
     EOL = b"\r\n"  # MicroPython EOL
 
@@ -109,7 +186,7 @@ class PybricksHub:
     has not been connected yet or the connected hub has Pybricks profile < v1.2.0.
     """
 
-    def __init__(self, device: BLEDevice):
+    def __init__(self, device: Union[BLEDevice, USBDevice]):
         self.connection_state_observable = BehaviorSubject(ConnectionState.DISCONNECTED)
         self.status_observable = BehaviorSubject(StatusFlag(0))
         self._stdout_subject = Subject()
@@ -155,7 +232,12 @@ def handle_disconnect():
             logger.info("Disconnected!")
             self.connection_state_observable.on_next(ConnectionState.DISCONNECTED)
 
-        self.client = PybricksHubBLEClient(device, disconnected_callback=handle_disconnect)
+        if isinstance(device, BLEDevice):
+            self.client = PybricksHubBLEClient(device, disconnected_callback=handle_disconnect)
+        elif isinstance(device, USBDevice):
+            self.client = PybricksHubUSBClient(device, disconnected_callback=handle_disconnect)
+        else:
+            raise TypeError
 
     @property
     def stdout_observable(self) -> Observable[bytes]:
@@ -308,7 +390,8 @@ async def connect(self):
                 )
 
             pnp_id = await self.client.read_gatt_char(PNP_ID_UUID)
-            _, _, self.hub_kind, self.hub_variant = unpack_pnp_id(pnp_id)
+            if pnp_id:
+                _, _, self.hub_kind, self.hub_variant = unpack_pnp_id(pnp_id)
 
             if protocol_version >= "1.2.0":
                 caps = await self.client.read_gatt_char(PYBRICKS_HUB_CAPABILITIES_UUID)