Hi to all viewers and members! can anybody help me or gave me any idea about parallel port interfacing that accepts input from a switch instead of keyboard and that input will be displayed in a seven segment.just a sample c program that has an input(inport) and ouput(outport) through the parallel port. Thanks more power to this site!!

Recommended Answers

All 10 Replies

Don't expect a lot of help from lvr on dot net subjects.
I got vb.net 2003. I've looked for over 2 years for code to turn on/off the individual pins of the paralle port. Nobody including lvr has ever helped. There is a program on lvr that checks the port, that's all it does. Nobody on Daniweb has either. Yes, I have the dll already, from logix4u.net. Anything but the code is just somebody trying to sound like they know all the answers.


The Windows operating system makes it more difficult than it should be. If I needed to use the parallel port, I'd look into Matlab, or maybe Python.

See what I mean. :-) And no info/code as to how to do it in thoes either. Gota love 'em. Two years of this bs. It's getting old fast.


Hi loimarie,

Did you make progress with your project.

Several hundred years ago I used a pico product called an ADC10. pico provided a 'driver' which was just some C that read the parallel port.

Google picoscope and go to their 'software' section and download the free adc10 driver if you're interested.



See what I mean. :-) And no info/code as to how to do it in thoes either. Gota love 'em. Two years of this bs. It's getting old fast.


I suggested Matlab, because it is what I would look into, I have it installed and I know it comes with libraries to use the PC ports. I didn't give any more info because everything is given in the help. If this isn't a good enough reason to suggest it, then I take it back.

Btw, the site that was linked offers a book written on the parallel port. Have you read it? You say you feel no one at Daniweb has helped you in two years. Then at what point might it have been a good idea to try another forum for help. Let me guess, you did and they couldn't help either. So I think I do see what you mean, it's everyone else's fault and not yours and the whole world is against you?

Good for you, I have vb.net2003 and c++.net. Why do I have to conform to your standard?

I have that book and read it ,clearly you didn't.

Yea , sure I'll google Matlab and see how much more money I have to spend.

For your information, I lost count at over 150 sites and forums.

People like you is why I hardly ever come to DaniWeb, and vary unlikely to come back.

Insert four letter woords here.


Real damn nice place you got here Dani !!!

I have that book and read it ,clearly you didn't.

Yes, I haven't. You're the one that needs to use the port not me.

Anyway, out of the interest in that it could take someone two years of trying and not be able to access the parallel port, I found a free ebook called, "My Experience In Parallel Port Interfacing" by Bibin John. It explains that Userport is needed, to allow direct access to the ports under NT based OSes, making the old DOS functions inportb() and outportb() work. I then found a thread which apparently verifies this. http://www.roboticsindia.com/modules.php?name=Forums&file=viewtopic&p=6428

I also found this page which shows you how to write to the parallel port in Java using Userport and another dll called Parport. With sample code.

Deep Sigh: It looks like you've put more than a little time in on this so I thank you. Take a look at inoup32.dll on logix4u.net. Inoutp32 uses a kernal mode driver. It does nearly the same thing as praport. I use this with the check port program on the lvr site. It works fine, however , it only checks the port and gives no clue as how to turn on/off individual pins.
I will look at that book and the page, though I expect I'll find yet another check port program.
I did check on matlab, I'm not that rich. Oh that were as easy as it is in old qbasic. Mostly I'm just trying to justify the vb.net2003, which so far has been a waste of money.


Be a part of the DaniWeb community

We're a friendly, industry-focused community of developers, IT pros, digital marketers, and technology enthusiasts meeting, networking, learning, and sharing knowledge.