traces

ccu_emulator/frames.py

@@ -0,0 +1,59 @@
+from __future__ import annotations
+
+from h8536.bench_connect_lcd import format_frame, frame_checksum, frame_checksum_ok, parse_frame
+
+
+FRAME_LENGTH = 6
+
+HEARTBEAT_FRAME = bytes.fromhex("0000000080DA")
+
+# Command 0, selector 0, value 0x8080. This seeds E000/E800 selector zero.
+ACTIVE_SEED_COMMAND0 = bytes.fromhex("00000080805A")
+
+# The older bench cadence sequence. It is still useful as an optional wake-up
+# strategy because the real panel proved timing-sensitive around these frames.
+CONNECT_CADENCE_SEQUENCE = (
+    bytes.fromhex("04000040001E"),
+    bytes.fromhex("0400008000DE"),
+    bytes.fromhex("040000C0009E"),
+)
+
+# Command 5, selector 0x0040, value ignored. ROM trace shows this is the safest
+# neutral report-consume candidate.
+NEUTRAL_ACK_FRAME = bytes.fromhex("05004000001F")
+
+
+def build_frame(command: int, selector: int, value: int) -> bytes:
+    """Build a six-byte host frame for simple page-0/page-1 selectors.
+
+    This helper covers the selector encodings we currently use in fake-CCU
+    probes. Keep more exotic mapping in one place when we learn it.
+    """
+
+    if not 0 <= command <= 0xFF:
+        raise ValueError("command byte out of range")
+    if not 0 <= selector <= 0x01FF:
+        raise ValueError("selector out of supported range 0x000-0x1FF")
+    if not 0 <= value <= 0xFFFF:
+        raise ValueError("value out of range")
+
+    if selector <= 0x007F:
+        byte1 = 0x00
+        byte2 = selector
+    elif selector <= 0x017F:
+        byte1 = 0x01
+        byte2 = selector - 0x0080
+    else:
+        byte1 = 0x02
+        byte2 = selector - 0x0180
+
+    frame = bytes(
+        [
+            command & 0xFF,
+            byte1 & 0xFF,
+            byte2 & 0xFF,
+            (value >> 8) & 0xFF,
+            value & 0xFF,
+        ]
+    )
+    return frame + bytes([frame_checksum(frame)])