using the parallel / serial port to drive 7-seg display

[Varnerjared]

OK, this may be lengthy. I have a 4 digit 7 segment display. There are several pins i need to drive this display. I need 36 serial pulses into one pin, and I need a clock to clock the data into the display into another pin. I want to use either the parallel or the serial port to do this.
My problem is this. I have a 4 digit number in labview. I want to send this number out of the parallel or serial port and have it displayed on the display. I dont think the serial port has a clock that i can use, but im not sure about the parallel port. If there is a VI or something to do this, it would be great. I am attaching the PFD of the displays data sheet to make sure that the operation of the display is clea
r.
Thanks guys

[Jeremy Braden]

If you are using the parallel port in ssp mode, you have 8 digital lines you can play with. Just use on of the lines for your clock.

I believe the other modes (ecp ,epp) of the port use a clock, but use it will be more trouble than it is worth. Toggling a digital line of an ssp port is very easy.

[Varnerjared]

Jeremy,
Thank you for starting my trial support membership with NI, it will greatly assist me in my project. I am horribly insufficient at working with the parallel port in labVIEW. You said that I can use ssp mode on the port...how do I do this? Please excuse my ignorance in this matter. Thanks again Jared

[Jeremy Braden]

I am lurking the discussion forum so my posting here is independent of whether you are on trial or not. In response to your email that you sent NI support, I activated your trial support period. This gives you 1 on 1 access to NI support engineers via email (like myself) or phone. The support I give here does not fall under the trial period privledges--I would still answer your question whether you had a subscription or not. Anyway....

You need to read up on the parallel port. Search the web for a tutorial. The last time I looked this information was readily avaliable.

There are 3 standard modes for the parallel port--ssp, epp, ecp. SSP is the original standard and is the easiest to use. You can set the mode of your parallel p
ort in your computer's BIOS. This is the config page you get by pressing special keys when your computer is starting. You can also confirm the setting in the device manager of Windows. You also need to do this so that you can get the memory address of the parallel port. Chances are it will be at x278 or x378. This is important so that you can know what memory address to have output update. There are 8 data lines in SSP mode and there are 8 bits (one byte) you can write to the memory address. Each bit you set will corespond to the port bring a line high. The idea is that you will be manipulating the bits of an 8 bit number and writing that value to the memory address. For your clock, you just write another value to the port with the clock line you choose toggled.

Jeremy
NI