aioble/central.py: Fix ScanResult.services when decoding UUIDs.

Fixes are needed to support the cases of:
- There may be more than one UUID per advertising field.
- The UUID advertising field may be empty (no UUIDs).
- Constructing 32-bit `bluetooth.UUID()` entities, which must be done by
  passing in a 4-byte bytes object, not an integer.

Signed-off-by: Damien George <damien@micropython.org>

micropython/bluetooth/aioble-central/manifest.py

@@ -1,4 +1,4 @@
-metadata(version="0.2.1")
+metadata(version="0.2.2")
 
 require("aioble-core")
 

micropython/bluetooth/aioble/aioble/central.py

@@ -195,12 +195,14 @@ class ScanResult:
 
     # Generator that enumerates the service UUIDs that are advertised.
     def services(self):
-        for u in self._decode_field(_ADV_TYPE_UUID16_INCOMPLETE, _ADV_TYPE_UUID16_COMPLETE):
-            yield bluetooth.UUID(struct.unpack("<H", u)[0])
-        for u in self._decode_field(_ADV_TYPE_UUID32_INCOMPLETE, _ADV_TYPE_UUID32_COMPLETE):
-            yield bluetooth.UUID(struct.unpack("<I", u)[0])
-        for u in self._decode_field(_ADV_TYPE_UUID128_INCOMPLETE, _ADV_TYPE_UUID128_COMPLETE):
-            yield bluetooth.UUID(u)
+        for uuid_len, codes in (
+            (2, (_ADV_TYPE_UUID16_INCOMPLETE, _ADV_TYPE_UUID16_COMPLETE)),
+            (4, (_ADV_TYPE_UUID32_INCOMPLETE, _ADV_TYPE_UUID32_COMPLETE)),
+            (16, (_ADV_TYPE_UUID128_INCOMPLETE, _ADV_TYPE_UUID128_COMPLETE)),
+        ):
+            for u in self._decode_field(*codes):
+                for i in range(0, len(u), uuid_len):
+                    yield bluetooth.UUID(u[i : i + uuid_len])
 
     # Generator that returns (manufacturer_id, data) tuples.
     def manufacturer(self, filter=None):

micropython/bluetooth/aioble/manifest.py

@@ -3,7 +3,7 @@
 # code. This allows (for development purposes) all the files to live in the
 # one directory.
 
-metadata(version="0.5.1")
+metadata(version="0.5.2")
 
 # Default installation gives you everything. Install the individual
 # components (or a combination of them) if you want a more minimal install.