# HG changeset patch
# User David Douard <david.douard@logilab.fr>
# Date 1467235087 -7200
# Node ID dcb6f3fcbd1eda0c85544c3e1d516628709d23d3
# Parent  64a7d3e2b2a81c426ac421847b253914581562db
[hp34970a] add some stuff on the flags decoding

diff -r 64a7d3e2b2a8 -r dcb6f3fcbd1e content/hp34970a_3.rst
--- a/content/hp34970a_3.rst	Sun Jun 26 01:32:13 2016 +0200
+++ b/content/hp34970a_3.rst	Wed Jun 29 23:18:07 2016 +0200
@@ -9,10 +9,10 @@
 :series_index: 3
 
 
-As explained in `the previous post in this series <{filename}/hp34970a_2.rst>`_, I've started to sniff the serial
-protocol between the main board and the display panel so I can replace
-the failed VFD by an OLED or TFT display managed by an arduino or
-similar.
+As explained in `the previous post in this series <{filename}/hp34970a_2.rst>`_,
+I've started to sniff the serial protocol between the main board and
+the display panel so I can replace the failed VFD by an OLED or TFT
+display managed by an arduino or similar.
 
 Protocol
 ========
@@ -44,12 +44,67 @@
 - ``<0x55>``: end of transmission.
 
 
-I've only identified 2 commands for now, but these are the most
+I've only identified 3 commands for now, but these are the most
 important ones:
 
 - ``0x00``: send the chars to the main display
 - ``0x0C``: send the chars to the secondary channel display
+- ``0x0A``: set the display indicators
 
+
+Main display
+------------
+
+Characters are simply sent to the display. However, to specify that a
+part of the string to display should be less bright (usually, the
+selected option is bright and the other ones are dim), the CPU insert
+a special character (need to check which hexadecimal value it is) at
+the beginning and the end of the dim part of the string.
+
+
+Channel display
+---------------
+
+Seems there is nothing special there. The frame payload always consist
+in 3 characters (the 3 digits).
+
+
+Indicator flags
+---------------
+  
+The indicator flags are always sent as 4 bytes, each bit controlling
+one indicator.
+
+The indicator flags I've been able to identify so far
+are below.
+
+Let's say the frame is: ``<0x0A> <0x04> <F1> <F2> <F3> <F4>``, then:
+
+
+- F1.7 = 
+- F1.6 = 
+- F1.5 = 
+- F1.4 = 
+- F1.3 = 
+- F1.2 = Mx+B enabled
+- F1.1 = Alarm enabled (or the alarm frame)
+  
+- F2.5 = 4W
+- F2.4 = 
+- F2.1 = 
+
+- F3.6 =
+- F3.5 =
+  
+- F4.7 = CONFIG (not sure)
+- F4.6 =
+- F4.5 = MON
+- F4.4 = VIEW
+- F4.3 =
+- F4.2 =
+- F4.1 = 
+
+  
   
 Quick prototype
 ===============