From mark.vandereynden at swiftdsl.com.au  Fri Apr 14 23:46:02 2006
From: mark.vandereynden at swiftdsl.com.au (Mark van der Eynden)
Date: Sat, 15 Apr 2006 13:46:02 +1000
Subject: [Micro-VGA] Micro-LCD questions
Message-ID: <000c01c6603f$249812b0$0a00000a@T1800>

Hi Don,
Long time no speak!
I'm on a PVR (HTPC) project at the moment and was investigating hooking
up a multi line LCD to display various information when I came across
your Micro-LCD and got to thinking 'Why use a 20x4 monochrome character
based LCD when I could use this?'. With a decent interface, every PVR
and HTPC would need one! 
Of course you would have to pre-package the display in a box with the
display at the front and the USB at the back, since many people would
have difficulty putting the thing together themselves, I'm thinking a
square box in a range of colors.
Most character based LCD displays use LCDSmartie
http://lcdsmartie.sourceforge.net/ to display information. This is
character based and would need expansion to cope with font information
not to mention graphics. But, as of the 1st of March 2006 development
has resumed, so one can only hope that they will be heading down the
graphical path real soon. 
Anyway, a couple of questions (probably more for Atilla):-
1. The requirement for the Power-Down command. When using the Micro-LCD
plugged into USB, the USB power might be permanent or it might not be.
I.e. 'Recording Next' information could be displayed whilst the PC is
hibernated. This would require the user to correctly configure the PC's
software to say if the Micro-LCD is 'Permanently Powered' or not and
users are generally not that reliable, especially when the consequences
are not immediately apparent. Wouldn't it be desirable to detect power
down on the Micro-LCD and turn off the voltage boosters and current
amplifiers automatically?

2. Speed. Assuming that the maximum speed over USB is effectively 128K
baud, to write a full graphical screen with the MK I will take about 6.4
seconds, so I presume that for a graphically intense application it
would be more desirable to go with the MK II and write everything to
flash before 'Run'ing it? Would this result in an apparent instantaneous
change?

3. That photo. The photo on page 5 of the user's manual shows text in a
31x18 configuration which is beyond they capabilities of a 5x7 font on a
128x128 display. What's going on here?

4. 'Place Text Character' command. I'm thinking this is the start of a
way to scroll larger size (both length and physical size) text across
the display. Does it allow -ve offsets to aid with this command?

5. I was thinking of alternating between 2 'programs' in flash. One is
executing (say with pseduo animation) whilst the other is being
downloaded. It would appear that this is not possible for two reasons 1.
Exit is the only valid command whilst executing flash and 2. Flash can
only be executed from location 0. Is this correct? I'm just trying to
get my head around how this might work.
Broken (incorrect link):- Half way down here
http://www.dontronics.com/micro-vga_group.html is a link to 'Micro-VGA
Archives' which points to
http://helene.affordablehost.com/pipermail/micro-vga_dontronics.com/
which is dead.
Well, that's it for now, I've got a lot more reading to do on how I
might make the PC software side of things work, looks like fun!
Mark