From 1981f7b475fabde63be55975e0e6deed9c321353 Mon Sep 17 00:00:00 2001
From: Martin Preuss <martin@aquamaniac.de>
Date: Wed, 5 Apr 2023 22:56:11 +0200
Subject: [PATCH] avr: added message format descriptions.

---
 avr/MESSAGES | 219 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 219 insertions(+)
 create mode 100644 avr/MESSAGES

diff --git a/avr/MESSAGES b/avr/MESSAGES
new file mode 100644
index 0000000..6bd2fc5
--- /dev/null
+++ b/avr/MESSAGES
@@ -0,0 +1,219 @@
+
+General Message Format
+======================
+
+Currently messages can maximally use 14 bytes for data because:
+- maximum buffer size if 16 bytes
+- the internal buffer needs an additional flags byte
+- a message contains a checksum byte
+
+
+Offset Length Meaning
+---------------------------------------------------------
+     0      1 destination address
+     1      1 remaining message length
+     2      1 command code
+     3      1 source address
+---------------------------------------------------------
+     4      n payload data (depending on command code)
+
+
+
+PING Message
+============
+
+Offset Length Meaning
+---------------------------------------------------------
+     0      1 destination address
+     1      1 remaining message length
+     2      1 command code
+     3      1 source address
+
+
+
+PONG Message
+============
+
+Offset Length Meaning
+---------------------------------------------------------
+     0      1 destination address
+     1      1 remaining message length
+     2      1 command code
+     3      1 source address
+
+
+
+Address Messages
+================
+
+This includes HAVE_ADDRESS, CLAIM_ADDRESS and DENY_ADDRESS.
+
+Offset Length Meaning
+---------------------------------------------------------
+     0      1 destination address
+     1      1 remaining message length
+     2      1 command code
+     3      1 source address
+---------------------------------------------------------
+     4      4 UID of the sending node
+     8      1 bus address
+
+
+
+RANGE Message
+=============
+
+Offset Length Meaning
+---------------------------------------------------------
+     0      1 destination address
+     1      1 remaining message length
+     2      1 command code
+     3      1 source address
+---------------------------------------------------------
+     4      1 first available address
+     5      1 last available address
+
+
+
+FLASH_START Message
+===================
+
+Offset Length Meaning
+---------------------------------------------------------
+     0      1 destination address
+     1      1 remaining message length
+     2      1 command code
+     3      1 source address
+---------------------------------------------------------
+     4      2 message number
+     6      2 address
+
+
+
+FLASH_ADDR Message
+==================
+
+Offset Length Meaning
+---------------------------------------------------------
+     0      1 destination address
+     1      1 remaining message length
+     2      1 command code
+     3      1 source address
+---------------------------------------------------------
+     4      2 message number
+     6      2 address
+
+
+
+FLASH_DATA Message
+==================
+
+Offset Length Meaning
+---------------------------------------------------------
+     0      1 destination address
+     1      1 remaining message length
+     2      1 command code
+     3      1 source address
+---------------------------------------------------------
+     4      2 message number
+     6      n up to 4 words to write at given address
+
+
+
+FLASH_END Message
+=================
+
+Offset Length Meaning
+---------------------------------------------------------
+     0      1 destination address
+     1      1 remaining message length
+     2      1 command code
+     3      1 source address
+---------------------------------------------------------
+     4      2 message number
+
+
+
+Flash_Response Message
+======================
+
+Offset Length Meaning
+---------------------------------------------------------
+     0      1 destination address
+     1      1 remaining message length
+     2      1 command code
+     3      1 source address
+---------------------------------------------------------
+     4      2 message number
+     6      1 response code (0 if okay, error code otherwise)
+
+
+
+VALUE2 Message
+==============
+
+Offset Length Meaning
+---------------------------------------------------------
+     0      1 destination address
+     1      1 remaining message length
+     2      1 command code
+     3      1 source address
+---------------------------------------------------------
+     4      4 UID of the sending node
+     8      1 value id
+     9      1 value type
+    10      2 value
+    12      2 denom
+
+
+
+DEVICE Message
+==============
+
+Offset Length Meaning
+---------------------------------------------------------
+     0      1 destination address
+     1      1 remaining message length
+     2      1 command code
+     3      1 source address
+---------------------------------------------------------
+     4      4 UID of the sending node
+     8      2 firmware type
+    10      2 firmware version
+    12      2 modules mask
+
+
+
+SENDSTATS Message
+=================
+
+Offset Length Meaning
+---------------------------------------------------------
+     0      1 destination address
+     1      1 remaining message length
+     2      1 command code
+     3      1 source address
+---------------------------------------------------------
+     4      4 UID of the sending node
+     8      2 packets out
+    10      2 collisions
+    12      2 aborted
+
+
+
+RECVSTATS Message
+=================
+
+Offset Length Meaning
+---------------------------------------------------------
+     0      1 destination address
+     1      1 remaining message length
+     2      1 command code
+     3      1 source address
+---------------------------------------------------------
+     4      4 UID of the sending node
+     8      2 packets in
+    10      2 errors
+    12      2 packets handled
+
+