Added hardware filter support for SeeedBus during initialization

Author: varunpenumudi

can/interfaces/seeedstudio/seeedstudio.py

@@ -63,6 +63,7 @@ def __init__(
         frame_type="STD",
         operation_mode="normal",
         bitrate=500000,
+        can_filters=None,
         **kwargs,
     ):
         """
@@ -85,6 +86,12 @@ def __init__(
         :param bitrate
             CAN bus bit rate, selected from available list.
 
+        :param can_filters:
+            A list of CAN filter dictionaries, where each dictionary contains
+            the keys 'can_id' and 'can_mask'. For the SeeedBus interface,
+            this list must not contain more than one filter. Defaults to None
+            (i.e., no filter).
+
         :raises can.CanInitializationError: If the given parameters are invalid.
         :raises can.CanInterfaceNotImplementedError: If the serial module is not installed.
         """
@@ -94,11 +101,23 @@ def __init__(
                 "the serial module is not installed"
             )
 
+        if can_filters is None:
+            can_filters = [{"can_id": 0x00, "can_mask": 0x00}]
+
+        if len(can_filters) > 1:
+            raise can.CanInitializationError(
+                f"The SeeedBus interface only supports one hardware filter, "
+                f"but {len(can_filters)} were provided."
+            )
+
+        # Get the first (and only) filter in can_filters
+        hw_filter = can_filters[0]
+
         self.bit_rate = bitrate
         self.frame_type = frame_type
         self.op_mode = operation_mode
-        self.filter_id = bytearray([0x00, 0x00, 0x00, 0x00])
-        self.mask_id = bytearray([0x00, 0x00, 0x00, 0x00])
+        self.filter_id = struct.pack("<I", hw_filter["can_id"])
+        self.mask_id = struct.pack("<I", hw_filter["can_mask"])
         self._can_protocol = CanProtocol.CAN_20
 
         if not channel:

doc/changelog.d/1995.added.md

@@ -0,0 +1 @@
+Added hardware filter support for SeeedBus during initialization.

doc/interfaces/seeedstudio.rst

@@ -44,7 +44,8 @@ Configuration
           timeout=0.1,
           frame_type='STD',
           operation_mode='normal',
-          bitrate=500000)
+          bitrate=500000,
+          can_filters=None)
 
 CHANNEL
  The serial port created by the USB device when connected.
@@ -75,3 +76,18 @@ BITRATE
  - 20000
  - 10000
  - 5000
+
+CAN_FILTERS
+  A list of can filter dictionaries. Defaults to None (i.e. no filtering).
+  Each filter dictionary should have the following keys:
+  - ``can_id``: The CAN ID to filter on.
+  - ``can_mask``: The mask to apply to the ID.
+
+  Example: ``[{"can_id": 0x11, "can_mask": 0x21},]``
+
+  **Hardware Limitation:** The Seeed Studio device only supports
+  a single hardware filter. This list must contain at most
+  one filter dictionary. A ``can.CanInitializationError`` will be
+  raised if more than one filter is provided.
+
+