[chbot] Lcd Problem

[Ben Devine]

On 1/18/07, Andrew Errington <a.errington@lancaster.ac.uk> wrote:
> On Thu, 18 Jan 2007 14:36, you wrote:
> > Hi,
> > Whilst this problem isnt robot related I thought this would be the
> > best place to ask.
> > I have been  lurking on this list for a while, Although this is my 1st
> > post.
>
> No worries- I think you'll find that there is a wealth of knowledge here
> beyond robots...
>
>
> > I made a simple LCD to LPT to practice my soldering skills but I have
> > come into a bit of a problem.
> > There seems to be some form of data/human error.
> >  Following
> > http://i.stole.all.the.rootservers.org/~ben/files/files/lcd44780.gif
> > wiring diagram.
> > It seems to work partially, I'm using a program called LCDsmartie to
> > get data out to it, Using it to avoid my windows(doing this at work so
> > no linux desktops) coding abilities be the issue.
> > http://lcdsmartie.sourceforge.net/
> > The settings I have set in it are
> > http://i.stole.all.the.rootservers.org/~ben/files/files/Settings.gif
> >
> > With the output being
> > http://i.stole.all.the.rootservers.org/~ben/files/files/DSCN0113.JPG
> >
> > I have checked all my wiring and configuration but I cannot pinpoint
> > the problem.
> > Does anyone have any suggestions,
>
> Well, the first thing I will say is if you are getting *anything* legible
> at all on the LCD module then you have no serious problems at all.  I have
> used these things in various sizes on many projects (and my lounge MP3
> player has one installed running off a PC parallel port much like yours).
>
> So, rather than being worried you should be immensely pleased- most people
> don't get this far on their first try.  It looks, therefore, like your
> problem is in the software...
>
> There are several common sizes of LCD module, 2x24 2x40 4x40 , etc., and
> the relationship between the internal memory map and what is actually
> displayed is often a bit funky.  Since you are not actually writing stuff
> to the LCD module directly it will be hard to track down the problem, but
> it may be a bug in LCDsmartie (I used LCDproc to control mine, but that's
> under Linux of course).  Does it work *without* the 'centre text' check
> box?  Have you tried a different LCD size from the drop-down box (i.e.
> different to 2x16)?
>
> I suggest you try an alternative program for driving the LCD, assuming you
> can find one that is compatible with the wiring scheme you have chosen.
> But at least the hardware is working.
>
> Here is a page that describes the modules in more detail.  This particular
> link takes you to the section regarding the memory map.  If the characters
> are being placed in the wrong area of memory (in the module) then they will
> show up in the wrong place on screen, or sometimes not at all.
>
> http://home.iae.nl/users/pouweha/lcd/lcd0.shtml#visible_ddram
>
> Clearly, when you wish to put some text at a specific place on the screen
> you have to know in advance the kind of module you are driving (which is
> why you need the drop down box).  I'd be surprised if there was a bug in
> LCDsmartie, and clearly you have selected the correct display size, but
> it's a possibility.  I'd also be surprised if your LCD module deviated from
> the de-facto standard for HD44780-based displays, but then, that's also
> possible (perhaps a Google for the specific chip number or part number on
> the back of your module will tell you).
>
> Good luck, and report back on your (imminent) success!
>
> Andrew
>
Hey, Andrew
Thanks for the speedy reply, I have sorted it,
In The end it was program error or I should say configuration error.
Whens the next robotics meeting btw, I would be rather interested in attending.



-- 
--Ben Devine