[lcdproc] HD44780

Joris Robijn joris@robijn.net
Tue, 31 Oct 2000 13:02:05 +0100


Hi Greg and all,

> Is anyone out there? Since I joined this list I have had one
> message?????

Almost same for me...

> It is just soooooo slow at updating. The client I am mainly using is
> irmp3 the lcdproc that comes with the server has a bug and runs once
> updates and dies.

I've seen this problem too. I wanted to write my own driver, 
independant of what others were developing (v0.5 or not). I've made 
some changes to the driver that was with the 0.4pre9 release. Can 
anyone of the active developers tell me what the status is of the 
HD44780 driver, and if my ideas (below) have not yet all been 
implemented (yet) ?

I've made these changes to the driver:
- Used 8-bit interface i.o. 4.
- Used another timing mechanism for the delays for changing the LPT-
lines (loops, I know, not prefereable :| We should have access to the 
kernel function udelay)
- Only update changed characters.
- Made it work with 4 keys, including software auto-repeat. The keys 
are on 4 input-lines of the LPT port. Very nice with the menus.

I got the avarage CPU-use down to less than 0.5% CPU time on my 
P188MMX. Most of the time it doesn't show up in `top`.

> Also at random times there will be a segmentation error.

I cannot remember having that problem.

> Any ideas on the above. I tried upping the 'frame rate' in main.h but
> this has not helped. The LCD is still updating at exactly the same speed
> ~~ 9 secs.

That constant is the speed at which the system _tries_ to get frames to 
the display.

Joris

-- 
 Joris Robijn <joris@robijn.net>
 Home: 053 4311 553
 Mobile: 06 288 41 964

 // To understand recursion, we must first understand recursion


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