RE: [Lcd4linux-devel] I2C modifications to HD44780 driver

[Luis.F.Correia <Lui...@se...>]

Hi Paul! 

> -----Original Message-----
> From: Paul Kamphuis [mailto:pau...@xs...] 
> Sent: Wednesday, March 30, 2005 8:01 AM
> To: Luis Correia; lcd4linux devel
> Subject: Re: [Lcd4linux-devel] I2C modifications to HD44780 driver
> 
> Hi Luis and Michael,
> 
> I did a check this morning. A 'normal' build doesn't enable the i2c 
> support as you both noticed. The reason for this is that in 
> the autoconf 
> phase of the build the include file linux/i2c-dev.h is not 
> detected as 
> valid. I am not sure of the reason but it has to do with the 
> way it is 
> validated by autoconf. I edited configure.in to return true 
> for the i2c 
> support even in the invalid case. It now builds nicely and 
> i2c support 
> is also enabled.
> Unfortunately doesn't work properly yet. I'll have to look 
> into it later 
> today. My guess is, that it has to do with the specification of the 
> ENABLE, RW, RS control signals. At least the observed behaviour seems 
> similar to what I had initialy.
> 

Well, all you will need to do is to create a setup similar to what is
in the lcd4linux.conf.sample, search for 'WRAP1C'.

Copy that definition, edit where appropriate and it should work.

You'll need to edit the i2c bus, the device address and where do
the signals go in terms of databus.

However, if your 4 data pins do not correspond to the lower 4 bus bits
(ie D0 - D3) then the code needs another rewrite, but it is doable.


> Later today I should have some more time to test.
> 
> Cheers,
> 
> Paul
> 

Tell me your thoughts on this!

Luis Correia