diff --git a/src/protocol.h b/src/protocol.h
new file mode 100644
index 0000000..49463b2
--- /dev/null
+++ b/src/protocol.h
@@ -0,0 +1,25 @@
+#ifndef protocol_h
+#define protocol_h
+
+#include <stdint.h>
+
+/*
+ * 79 00 03 00 06 00 9C 76 B6 07 00 00 D4 00 00 00    y......v¶...Ô...
+ * 02 00 00 00 39 00 00 00 63 F9 FF FF 00 00 00 00    ....9...cùÿÿ....
+ * 41 43 51 20 53 74 61 72 74 65 64 2C 20 41 52 46    ACQ.Started,.ARF
+ * 43 4E 3D 25 64 2C 20 52 78 50 57 52 78 31 36 3D    CN=%d,.RxPWRx16=
+ * 25 64 00 6C 31 5F 61 63 71 2E 63 00                %d.l1_acq.c.
+ */
+
+struct ext_log_msg {
+	uint8_t		type;
+	uint16_t	unknown1;	/* 0x00 0x03 type??? */
+	uint16_t	unknown2;	/* 0x00 0x06 type??? */
+	uint64_t	timestamp;	/* More 32 bit but dm-commands.h */
+	uint8_t		unknown3[3];	/* 0x00 0x00 0x00 */
+	uint32_t	unknown4;	/* 0x02 0x00 0x00 0x00 */
+	int32_t		params[3];	/* three params */
+	uint8_t		data[0];	/* two NULL terminated strings from here */
+} __attribute__((packed));
+
+#endif