[C++] Parallel I/O

[GatorV]

Hi, I have been searching for a good tutorial on how to perform I/O to the Parallel Port (LPT1), but had no luck :(, can any one recomend one?

Thanks in Advance :D

[Andareed]

What OS? If you use windows, you should be able to use CreateFile and specify file = "LPT1". From MSDN:

hCom = CreateFile("LPT1",

GENERIC_READ | GENERIC_WRITE,

0, // must be opened with exclusive-access

NULL, // no security attributes

OPEN_EXISTING, // must use OPEN_EXISTING

0, // not overlapped I/O

NULL // hTemplate must be NULL for comm devices

);

You can then use ReadFile and WriteFile and treat LPT1 just like a file.

[GatorV]

Thanks I am using Windows, basically I want to send a high bit to certain pins, this is for a hardware thing, and I wan't to simulate a button press on the Board, via the LPT1 device.

Thanks :cool:

[GatorV]

BUMP, anyone??

[azcodemonkey]

You'll probably need to use DeviceIoControl to access specific ports on the parallel connector. Look for IOCTL_PAR_SET_READ_ADDRESS and IOCTL_PAR_SET_WRITE_ADDRESS. You'll probably need to use a few other operations, too.

http://msdn.microsoft.com/library/en-us/pa....asp?frame=true

[Andareed]

Shouldn't ReadFile/WriteFile work? Those IOCTL's seem only relavent when dealing with ecp or epp mode. In any case, you'll need to use DeviceIoControl with the IOCTL's mentioned by weenur.

[azcodemonkey]

I don't know. I'm only guessing. Can you specify port in WriteFile?

[Andareed]

No idea either ;) Parport.sys source (or something useful) might be included in some windows ddk though. You could check this for a definative answer.