big refactor of waveform protocol.

minimateplus/models.py

@@ -201,6 +201,58 @@ class Timestamp:
             second=second,
         )
 
+    @classmethod
+    def from_short_record(cls, data: bytes) -> "Timestamp":
+        """
+        Decode an 8-byte timestamp header from a 210-byte waveform record.
+
+        Wire layout (✅ CONFIRMED 2026-05-01 against live SFM run on BE11529 in
+        Continuous mode, day-of-month = 1 May, raw: 01 05 07 ea 00 0d 15 25):
+          byte[0]:    day                 (uint8)
+          byte[1]:    month               (uint8)
+          bytes[2-3]: year                (big-endian uint16)
+          byte[4]:    unknown             (0x00 in observed sample)
+          byte[5]:    hour                (uint8)
+          byte[6]:    minute              (uint8)
+          byte[7]:    second              (uint8)
+
+        This is a third format observed in the wild — distinct from the 9-byte
+        (single-shot, sub_code=0x10 at [1]) and 10-byte (continuous, 0x10 at
+        [0] AND [2]) layouts.  No marker bytes; disambiguated by where the
+        year lands when scanned at byte 2/3/4.
+
+        Args:
+            data: at least 8 bytes; only the first 8 are consumed.
+
+        Returns:
+            Decoded Timestamp.
+
+        Raises:
+            ValueError: if data is fewer than 8 bytes.
+        """
+        if len(data) < 8:
+            raise ValueError(
+                f"Short record timestamp requires at least 8 bytes, got {len(data)}"
+            )
+        day          = data[0]
+        month        = data[1]
+        year         = struct.unpack_from(">H", data, 2)[0]
+        unknown_byte = data[4]
+        hour         = data[5]
+        minute       = data[6]
+        second       = data[7]
+        return cls(
+            raw=bytes(data[:8]),
+            flag=0,
+            year=year,
+            unknown_byte=unknown_byte,
+            month=month,
+            day=day,
+            hour=hour,
+            minute=minute,
+            second=second,
+        )
+
     @property
     def clock_set(self) -> bool:
         """False when year == 1995 (factory default / battery-lost state)."""