[Lcd4linux-devel] Re: [Fwd: Graphics support for Cwlinux]

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

Hi Xavier, Hi List (if you ever get this one)

> Hello Michael. As SF MLs have problems, I forward you this mail I posted on the ML.
Right. Looks like SF having enough problems at the moment...

> As the command to put one pixel is at least 5bytes long and the
> transfert rate is 19200, it takes about 30seconds to write all the
> display :/

I want to get to know the guy who designed this interface. I'd have some 
wet towels with me...

> But there are some interesting features :
> - The display can handle text, bars (without user characters) and
> graphics togethed, so we can have some text, draw bars and display some
> pixmap with the rest of the bandwith.

Yes, that's right. We should use the "generic text" driver as a basis, 
which handles text, bar (and probably icon) widgets. But the driver may 
provide further "graphical" widgets...

> - It support also 'inverted text', that's a good thing, for example if a
> temperature hits a predefined maximum value, you should add such and
> option to the text widget (and use it if the display supports it)
Good idea! Today another attribute came to my mind: blinking!

> Do you think it's possible to implement a time-based graph widget, and a
> sort of 'fixed pixmap' widget (but which format to use for images ?) ?
Everything is possible!
- I want not only a time-based graph, but a general graph where x and y 
can be any expressions.
- A "image" widget would be great! I'm going to prepare a photo of mine :-)

> Moreover, GPIs are read on demand, so should we write a
> plugin_cwlinux_gpi or add the function within the drv_cwlinux ? I don't
> know your position on this point.

I'm not shure either. I think it does not make much of a difference what 
kind of input you handle: a GPI, a tenmperature sensor, a fan sensor, or 
a keypad. OTOH, the first would be all simple plugins or functions, the 
latter should trigger an event.
Hmmm... I think a GPI should be a function. And there sould be no 
plugin_*.c for this, but the function should be inside of drv_Cwlinux.c 
(as other plugins are at the moment, take a look at drv_MatrixOrbital).

> There's still the problem of keypad handling, as the display sends the
> keys directly, the driver should always be able to read this values.
> Where can we implement this read ? directly drv ? plugin ? keypad.c ?
Hmmm.. Give me some time on this issue. I've got three displays here 
with a keypad, I'll have to go through all these datasheets, and try to 
find a "common" solution.

bye, Michael

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