[Lcdproc] Improvements to imon driver: special characters and smoother hbar

Otto Kolsi otto@kolsi.fi
Wed May 30 06:09:02 2007


I'm using latest LCDproc 0.5.2 with FC5 and MythTV and have
Silverstone LC11M case, so I'm using imon driver with the LCDproc.

I've wondered some time why scandinavic characters (äö) are not
displayed correctly with LCDproc. It turns out that VFD is capable of 
showing 'ä' and 'ö' characters but those are mapped to different 
characters than in ISO-8859-1 (0xE4, 0xF6).

I created a cuick and dirty modification so that imon driver converts 
incoming "ä,Ä,ö,Ö" to the characters that work for my display. Is this 
really so that you need to fix the driver.. and this is not some kind of 
setup/configuration problem that I'm having? If this is not a 
configuration issue, could these kind of mappings be supported in LCDproc?


Another issue I noticed is that horizontal bar could be drawn more
nicely (IMHO). Now it outputs either ' ', '|', '>' or '#' (last one is
not that char but sort of full block). When I went through the 
characters of the display, I noticed that it can
output more useful characters where there are 1-5 vertical bars present
(within one character): '|', '||', ... I changed the hbar
function in imon driver to use these characters and I think it is now 
nicer. The progress is smoother.

When I looked at the imon driver and especially the hbar function, I
got the feeling that different devices working with imon probably output
  slightly different characters. E.g. in the imon.c imon_hbar(), 
IMON_CHAR_PLAY and '>' are used to draw the partial block progress. I 
definitely don't see any 'play character', I only see '>' and '|'. I can 
output character that is probably meant by IMON_CHAR_PLAY, but that is 
not character 0x10 as currently is in imon.c.

Any ideas what this is all about? Is it a bug or does different devices 
output slightly different special characters when used with imon driver? 
If so.. should we support these different variations within the imon driver?

MythTV's Wiki suggests that there are several different types of iMon 
VFD displays: http://www.mythtv.org/wiki/index.php/Imon
-- 
   Otto