[Lcd4linux-devel] HD44780 stuff

[Michael R. <re...@eu...>]

Hi Bill, Hi List (especially Martin and Xavier),

I just commitet a new HD44780 driver, with some major changes:

- we now support a "Models" table with "Capabilities"

- I added a Model "Soekris" with the Capability "BUSY4BIT". Martin, 
please check the functiuonality, and rename the Model according to your 
wishes

- I integrated Bill's Noritake Brightness level patch; I added a Model 
"Noritake" with the Capability "BRIGHTNESS".

Bill, I didn't really understand your code here:

    snprintf (tmpbuffer, 2, "\%o", cu_vfd_brightness);
What the heck is "\%o"? Is it octal? Why the backslash? What does the 
resulting string look like?

It gets even more strange:
    HD_write (0x03, tmpbuffer, 1, T_WRCG);
If the abofe format string is correct, the brightness would be in the 
second character. But you're sending only one byte (the backslash).

I suppose the backslash was a typo. But please double-check the code in 
drv_HD44780.c Thanks!


> So, the 'NextGen' conf could go something like:
> 
> Display HD44780
> Model CU4002
> CUBrightness 2

it would be
   Model Noritake
   Brightness 2

>>I wondered about these three fine vertical lines
> Exactly, filament lines. Think audio valves. Same deal.
Great! Really Great!
Should we implement this in the X11 driver?

> BTW: Is anyone working on asserting SEL for backlight
> control of HD44780 modules like lcdproc and lcdmod?
> I guess it could be any of the available outputs pins.
> I was just doing it for SEL. AFAIK everyone wired the
> transistor to SEL.

This is on my ToDo-List (at least on the ony in my head)

> The question is, do they want to control it just at
> HD_init and HD_quit, or be able via codes or time
> of day or event trigger, etc?

Both. I finally decided how to handle all this Contrast, Backlight and 
so on features:

- a value will be read from the config at init time, if there is one, 
the function will be called

- the feature should register as a plugin, and there will be something 
like "events" or "timers" which you can individually define from the config

There's something special about these plugins: They do not just return a 
value, but actively change something: for example a Contrast() function 
would return the current contrast, but set it, too.

Finallly, sometime it will look like this:

Handler "Backlight" {
    Type Timer
    Update 1000
    Action 'backlight(2*loadavg(1))'
}

Which means that every 1 second the backlight will be set accordingly to 
the current load.


bye, Michael

-- 
Michael Reinelt                                   Tel: +43 676 3079941
Geisslergasse 4                                   Fax: +43 316  692343
A-8045 Graz, Austria                          e-mail: re...@eu...