[amsat-bb] Re: [SPAM] Re: LVB tracker display problem

13 Jan 2008

      Hello Andrew,
The R/W line to the HD44780 LCD controller allows you to switch between 
write and read data from the LCD.  There are commands to get data from 
CGRAM, read DDRAM  and also read the Busy flag.  All of Howard's code for 
LVB Tracker is on his web site.  http://www.g6lvb.com
73,
Gould, WA4SXM
----- Original Message ----- 
From: "Andrew Rich" vk4tec@people.net.au
To: "Howard Long" howard@howardlong.com; heliox694-iw1dtu@yahoo.com; 
"'AMSAT'" amsat-bb@amsat.org
Sent: Sunday, January 13, 2008 2:25 PM
Subject: [amsat-bb] Re: [SPAM] Re: LVB tracker display problem
...
Howard,
How does the LVB detect an LCD presence ?
In all the LCD programming I have ever done, it has been just logic levels
towards the LCD.
Nothing in return ?
Are you talking to the LCD CPU ?

Andrew Rich VK4TEC
vk4tec@people.net.au mailto:vk4tec@people.net.au
http://www.tech-software.net
-----Original Message-----
From: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org]On
Behalf Of Howard Long
Sent: Sunday, 13 January 2008 7:53 PM
To: heliox694-iw1dtu@yahoo.com; 'AMSAT'
Subject: [SPAM] [amsat-bb] Re: LVB tracker display problem
Importance: Low
Hi Fer
...
I just finish to build an LVB tracker for a friend
of mine. All works fine with NOVA but during a satellite
pass the display stuck as in the picture:
I am not aware of a similar problem occuring. I wonder if it is possible 
to
temporarily try a different display?
There is a section of code that attempts to detect whether an LCD exists 
or
not, for those who don't use the LCD option. If at any point it takes more
than 5ms to get a response from the LCD the software assumes there isn't 
one
there and won't attempt to update the display again, until the tracker is
reset.
However, looking at the display, it looks like the LCD may have somehow
reset itself. This could make the software think that the LCD has been
removed: a special startup sequence is needed to configure these LCDs 
after
a reset.
Again, try a different LCD if possible, then check the power supply to the
LCD is nice and stable without any glitches.
Also, if you simply press the reset push button, rather than cycle the
power, does the display work correctly then? This initiates the LCD
reconfiguration.
73, Howard G6LVB

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[amsat-bb] Re: [SPAM] Re: LVB tracker display problem

Gould Smith