[Lcdproc] lcdserializer problems

[Matteo Pillon]

--ZPt4rx8FFjLCG7dd
Content-Type: text/plain; charset=iso-8859-15
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

On Mon, Aug 07, 2006 at 12:17:48AM +0200, Christian Kruft wrote:
> I'm going to expand the ASM to work with LCDs which have 4 lines - i.e.=
=20
> 2 Enable-Pins. Do u have any suggestions how  to do?

Do you really need 2 controllers? 4x20 is usually built with only one
controller (one enable pin).

> I think the driver should send another new byte to select Enable of
> controller 1 or Enable of controller 2- can u make such a driver?

I think that wouldn't be too hard to do. Do you really need it?

> U can name it "vdr-lcd" and please drop the reinit.

I tink reinit is useful, because there are not only hd44780 displays
out there, but also almost-compatible ones, that need a different init
to work well (like the extended mode of ks0073). Only if you implement a
way to choose init in the hardware (a jumper, for example), software
reinit doesn't make sense anymore.

> Also a full refresh after some time would be great (but pls send a
> clear before any text).

Why do you want this?

> When the driver is working, I could do it easily and make it
> public. Maybe 0xFC Enable (controller 1) and 0xFD Enable (controller
> 2) ? 0xFE is command mode and 0xFF I use for another thing.

Uhmm, 0xFD and 0xFF correspond to useful characters in the hd44780
charmap and very useful in the ks0073 one (curly braces).
The escape approach of lcdserializer is not so much extendible,
pic-an-lcd has a more well-thought design.
It uses 2 escape codes, one for instructions (0x11) and one for data
(0x12). The latter is used only when the character to send is less
than 0x20.
This reduces overload from data escape and allows to use escape codes
for something else up to 0x20.

Bye.

--=20
 * Pillon Matteo

--ZPt4rx8FFjLCG7dd
Content-Type: application/pgp-signature
Content-Disposition: inline

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.4 (GNU/Linux)

iD8DBQFE15YJdF6kRp1ZHz0RAqHYAJ9RN+ZsHsvDwqZDWvBtOgUZ+pf08QCfbzYI
2uAyp/Ep0XhSsRN/h3+ryN0=
=FQb1
-----END PGP SIGNATURE-----

--ZPt4rx8FFjLCG7dd--