Re: Raspberry Pi as an inexpensive embedded LCDproc server

On 24.08.2012 15:58, paul_c wrote:
> On Sunday 19 August 2012, Markus Dolze wrote:
>> Please base patches against CVS HEAD (or a nightly build).
> Patch version 2. Main differences are:
>
> * diff'd against today's CVS source tree.
> * Raspberry Pi gpio pins can be specified in the config file.
> * Fixed a few issues with garbage being displayed on one LCD module.
>
> Still to do:
>
> * Document.
> * Include autoconf tests for ARM targets and Raspberry Pi specifically.
> * Add support for 8bit modules.
> * Support multiple LCDs
> * Add support for i2c connected LCDs.
>
>
> Regards, Paul.
>

Hi,

I haven't done any research yet - is there a GPIO framework for Linux
one can use instead of rolling our own?

How does the 'uname' of a Pi system looks like? Can $host in
configure.in be used to detect the Pi?

Before adding support for I2C you should really consider using
hd44780-i2c instead, as Jannis pointed out that it already can drive
displays on the Pi. I'd like to avoid rolling our own I2C thing if one
already  works.

If possible I would like to get rid of the global *gpio_map. I try to
keep sub-drivers clean from things like these if possible. If you need a
'private' pointer put it in hd44780_private_data. This is crowded
already - anyway, I will be fine with it.

Regarding delays and timings: Unless you need 'exact' timings (like 150
CPU cycles), uPause() should be sufficient and is easier to understand.

Have a nice day,
Markus