Implement the remaining canopen datatypes (#440)

* Implement the remaining canopen datatypes
* Add datatype defs for the canopen standard types
* Move datatypes_24.py classes to datatypes.py
* Replace Unsigned24 and Interger24 by generic UnsignedN and IntegerN respectively
* Add EDS-file containing all datatypes
* Added tests for encoding and decoding all datatypes
* Added tests for SDO uploads of all datatypes
* Annotate type hint for STRUCT_TYPES listing.
* Disable failing tests waiting on a fix for #436.

Co-authored-by: André Colomb <[email protected]>

Author: sveinse

canopen/objectdictionary/__init__.py

@@ -9,7 +9,6 @@
 import logging
 
 from canopen.objectdictionary.datatypes import *
-from canopen.objectdictionary.datatypes_24bit import Integer24, Unsigned24
 from canopen.utils import pretty_index
 
 logger = logging.getLogger(__name__)
@@ -282,17 +281,25 @@ def add_member(self, variable: ODVariable) -> None:
 class ODVariable:
     """Simple variable."""
 
-    STRUCT_TYPES = {
+    STRUCT_TYPES: dict[int, struct.Struct] = {
+        # Use struct module to pack/unpack data where possible and use the
+        # custom IntegerN and UnsignedN classes for the special data types.
         BOOLEAN: struct.Struct("?"),
         INTEGER8: struct.Struct("b"),
         INTEGER16: struct.Struct("<h"),
-        INTEGER24: Integer24(),
+        INTEGER24: IntegerN(24),
         INTEGER32: struct.Struct("<l"),
+        INTEGER40: IntegerN(40),
+        INTEGER48: IntegerN(48),
+        INTEGER56: IntegerN(56),
         INTEGER64: struct.Struct("<q"),
         UNSIGNED8: struct.Struct("B"),
         UNSIGNED16: struct.Struct("<H"),
-        UNSIGNED24: Unsigned24(),
+        UNSIGNED24: UnsignedN(24),
         UNSIGNED32: struct.Struct("<L"),
+        UNSIGNED40: UnsignedN(40),
+        UNSIGNED48: UnsignedN(48),
+        UNSIGNED56: UnsignedN(56),
         UNSIGNED64: struct.Struct("<Q"),
         REAL32: struct.Struct("<f"),
         REAL64: struct.Struct("<d")
@@ -386,10 +393,13 @@ def add_bit_definition(self, name: str, bits: List[int]) -> None:
 
     def decode_raw(self, data: bytes) -> Union[int, float, str, bytes, bytearray]:
         if self.data_type == VISIBLE_STRING:
-            return data.rstrip(b"\x00").decode("ascii", errors="ignore")
+            # Strip any trailing NUL characters from C-based systems
+            return data.decode("ascii", errors="ignore").rstrip("\x00")
         elif self.data_type == UNICODE_STRING:
-            # Is this correct?
-            return data.rstrip(b"\x00").decode("utf_16_le", errors="ignore")
+            # The CANopen standard does not specify the encoding. This
+            # library assumes UTF-16, being the most common two-byte encoding format.
+            # Strip any trailing NUL characters from C-based systems
+            return data.decode("utf_16_le", errors="ignore").rstrip("\x00")
         elif self.data_type in self.STRUCT_TYPES:
             try:
                 value, = self.STRUCT_TYPES[self.data_type].unpack(data)
@@ -407,8 +417,9 @@ def encode_raw(self, value: Union[int, float, str, bytes, bytearray]) -> bytes:
         elif self.data_type == VISIBLE_STRING:
             return value.encode("ascii")
         elif self.data_type == UNICODE_STRING:
-            # Is this correct?
             return value.encode("utf_16_le")
+        elif self.data_type in (DOMAIN, OCTET_STRING):
+            return bytes(value)
         elif self.data_type in self.STRUCT_TYPES:
             if self.data_type in INTEGER_TYPES:
                 value = int(value)

canopen/objectdictionary/datatypes.py

@@ -1,3 +1,4 @@
+import struct
 
 BOOLEAN = 0x1
 INTEGER8 = 0x2
@@ -10,16 +11,116 @@
 VISIBLE_STRING = 0x9
 OCTET_STRING = 0xA
 UNICODE_STRING = 0xB
+TIME_OF_DAY = 0xC
+TIME_DIFFERENCE = 0xD
 DOMAIN = 0xF
 INTEGER24 = 0x10
 REAL64 = 0x11
+INTEGER40 = 0x12
+INTEGER48 = 0x13
+INTEGER56 = 0x14
 INTEGER64 = 0x15
 UNSIGNED24 = 0x16
+UNSIGNED40 = 0x18
+UNSIGNED48 = 0x19
+UNSIGNED56 = 0x1A
 UNSIGNED64 = 0x1B
+PDO_COMMUNICATION_PARAMETER = 0x20
+PDO_MAPPING = 0x21
+SDO_PARAMETER = 0x22
+IDENTITY = 0x23
 
-SIGNED_TYPES = (INTEGER8, INTEGER16, INTEGER24, INTEGER32, INTEGER64)
-UNSIGNED_TYPES = (UNSIGNED8, UNSIGNED16, UNSIGNED24, UNSIGNED32, UNSIGNED64)
+SIGNED_TYPES = (
+    INTEGER8,
+    INTEGER16,
+    INTEGER24,
+    INTEGER32,
+    INTEGER40,
+    INTEGER48,
+    INTEGER56,
+    INTEGER64,
+)
+UNSIGNED_TYPES = (
+    UNSIGNED8,
+    UNSIGNED16,
+    UNSIGNED24,
+    UNSIGNED32,
+    UNSIGNED40,
+    UNSIGNED48,
+    UNSIGNED56,
+    UNSIGNED64,
+)
 INTEGER_TYPES = SIGNED_TYPES + UNSIGNED_TYPES
 FLOAT_TYPES = (REAL32, REAL64)
 NUMBER_TYPES = INTEGER_TYPES + FLOAT_TYPES
 DATA_TYPES = (VISIBLE_STRING, OCTET_STRING, UNICODE_STRING, DOMAIN)
+
+
+class UnsignedN(struct.Struct):
+    """Packing and unpacking unsigned integers of arbitrary width, like struct.Struct.
+
+    The width must be a multiple of 8 and must be between 8 and 64.
+    """
+
+    def __init__(self, width: int):
+        self.width = width
+        if width % 8 != 0:
+            raise ValueError("Width must be a multiple of 8")
+        if width <= 0 or width > 64:
+            raise ValueError("Invalid width for UnsignedN")
+        elif width <= 8:
+            fmt = "B"
+        elif width <= 16:
+            fmt = "<H"
+        elif width <= 32:
+            fmt = "<L"
+        else:
+            fmt = "<Q"
+        super().__init__(fmt)
+
+    def unpack(self, buffer):
+        return super().unpack(buffer + b'\x00' * (super().size - self.size))
+
+    def pack(self, *v):
+        return super().pack(*v)[:self.size]
+
+    @property
+    def size(self) -> int:
+        return self.width // 8
+
+
+class IntegerN(struct.Struct):
+    """Packing and unpacking integers of arbitrary width, like struct.Struct.
+
+    The width must be a multiple of 8 and must be between 8 and 64.
+    """
+
+    def __init__(self, width: int):
+        self.width = width
+        if width % 8 != 0:
+            raise ValueError("Width must be a multiple of 8")
+        if width <= 0 or width > 64:
+            raise ValueError("Invalid width for IntegerN")
+        elif width <= 8:
+            fmt = "b"
+        elif width <= 16:
+            fmt = "<h"
+        elif width <= 32:
+            fmt = "<l"
+        else:
+            fmt = "<q"
+        super().__init__(fmt)
+
+    def unpack(self, buffer):
+        mask = 0x80
+        neg = (buffer[self.size - 1] & mask) > 0
+        return super().unpack(
+            buffer + (b'\xff' if neg else b'\x00') * (super().size - self.size)
+        )
+
+    def pack(self, *v):
+        return super().pack(*v)[:self.size]
+
+    @property
+    def size(self) -> int:
+        return self.width // 8