[Linux-parport] Parallel port specific questions

Sami Tapio flexy at ee.oulu.fi
Sun Dec 12 11:23:55 EST 2004


I managed to get my self stuck with one project, which involves parallel port 
polling or IRQs. Let me get a little more specific. Ummh, TOTALLY non profit 
project, if somebody is wondering...

Laptop, ~100MHz Pentium, parallel port. What is needed from it? As precise info 
about 4 input pins on parallel port as possible. Precise? Yes, time precise. As in, 
1ms accurate information on when and which pin changed state. 1us would be better, 
but propably that is way out of the capabilities of the laptop... The info could 
be written to a file, for example... easy to use it with shell scripts :)

So, propably kernel module would get the most out of HW, ppdev according to my 
studying of the subject, could be one solution?

I'm thinking of using 2.6.x kernel, what kernel options should be considered 
for the timing accuracy to be the most that is possible for this HW? (Pre emptible, 
etc) I can manage to do the "UI" and other stuff needed, with shell scripts etc, 
but with this... I'm lost.

My C-programming capabilities are non existent, so this is kind of desperate 
call of help :) 

Any hints, programming examples, or even working code for this purpose would 
be greatly appreciated. 

Best Regards,


P.S. Please include me on CC list when answering. Thanks.

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