[En-Nut-Discussion] ethernut board 3.1 LCD support

[Ulrich Prinz]

Hi Paul!

Am 11.05.2010 10:30, schrieb Paul Govers:
>
> Hi Ulrich,
>
> Thats great that you working on an LCD driver for the ethernut 3.1 board!
> i will try tonight to get my LCD display working with my Ethernut 3.1 board,
> i have read the documentatie about the HD44780 and it seems not to difficult
>
I replaced the driver for AT91, it is not specialized on the EN 3.1 but 
it should work with all AT91 devices.
It uses GPIO for all signals and, in this release, will not support 
reading from the display. And this is something you might want, as the 
CPU on the EN 3.1 has no 5V tolerant pins. Reading without 
level-shifters will destroy the CPU if the display is driven with 5V. On 
the other hand you might use the CPLD as a level shifter, it is 5V 
tolerant even driven with 3.3V or less.

I think I don't have time tonight for checking in my driver, but I will 
do it tomorrow night for sure. I actually think for adding another 
access method, the memory interface. I didn't check the data sheets of 
all AT91 if they can be programmed for such slow memories and if they 
are able to drive an active-high chip select.

Best regards, Ulrich