--- /dev/null
+/* HomeMatic defines
+ *
+ * Copyright (c) 2014 Michael Gernoth <michael@gernoth.net>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#define LEN 0x00
+#define MSGID 0x01
+#define CTL 0x02
+#define TYPE 0x03
+#define PAYLOAD 0x0a
+
+#define SRC(buf) (buf[0x06] | (buf[0x05] << 8) | (buf[0x04]) << 16)
+#define DST(buf) (buf[0x09] | (buf[0x08] << 8) | (buf[0x07]) << 16)
+
+#define SET_SRC(buf, src) do { buf[0x04] = (src >> 16) & 0xff; buf[0x05] = (src >> 8) & 0xff; buf[0x06] = src & 0xff; } while(0)
+#define SET_DST(buf, dst) do { buf[0x07] = (dst >> 16) & 0xff; buf[0x08] = (dst >> 8) & 0xff; buf[0x09] = dst & 0xff; } while(0)
+
+#define SET_LEN_FROM_PAYLOADLEN(buf, payloadlen) do { buf[0x00] = payloadlen + 0x09; } while(0)