Running LEDs from a Parallel Port

[rickalty]

Some time ago - either here or elsewhere - I stumbled upon an article on how to display MSFS outputs on 7-seg LEDs run from the computers Parallel Port. I now can't find this info again :-(Can anyone help me out with a link ?Rick

[Guest]

What you are looking for is a filed called : FSdigit. This can be found in the Avsim library. The circuit uses a MAX7219 and is linked to the parallel port. For driving it you need a parallel port device driver like tvichw32.zip. Then you need codes that reads from FS and that is what blocks me to make this work ( I am not a programmer). Maybe someone can help you here ( and me at the same time ).

[Guest petdocvmd]

Guys, stay tuned for a new parallel port device that will drive at least seven (and possibly up to 28) 8-digit seven-segment displays as well as several hundred single LEDs. It will also feature 128 inputs (possibly more in the future).I will be making the schematics for building this device freely available once completed. It too is based upon the MAX 7219 but uses a freeware PPT driver compatible with Win2000/XP. I will make software class libraries of functions (.Net) to drive it available as freeware as well.I anticipate a release date within the next month or so (I hope ). I'll post an advisory in this forum. Prebuilt boards for those averse to soldering as well as software for non-programmers may be available for a reasonable fee as well if there is interest.Cheers,Scott Fausel>What you are looking for is a filed called : FSdigit. This>can be found in the Avsim library. The circuit uses a MAX7219>and is linked to the parallel port. For driving it you need a>parallel port device driver like tvichw32.zip. Then you need>codes that reads from FS and that is what blocks me to make>this work ( I am not a programmer). Maybe someone can help you>here ( and me at the same time ).

[rickalty]

Sounds great..... but won't help me :-(.NET won't run under W98, and I can't upgrade because I have a legacy video editing setup that isn't compatible with anything newer than W98 Richard

[Guest LeoL]

Richard, sorry to hear you're still stuck with Win98. In that case, you'll want to stay away from my latest version of KB Studio for your 64B. It simply won't read the inputs properly under Win98.I've since upgraded to XP and had to give up 98 (wouldn't install otherwise), but why not upgrade to 2000 with a dual boot manager and still keep Win98 for your video editing setup? Are the video card drivers only Win98 compatible?-Leo

[Guest RichardL]

Hi Scott,Interesting project. Any chance you might change from a parallel port input to USB?Richard

[rickalty]

I'm thinking going to dual-boot may be the way to go, Leo. It's not a video card issue - it's an external mixer (Basically a box of memory that holds a 'buffer' of multiple video streams so that you can do fades / wipes / bluescren effects) whose drivers are only W98 compatible. By the way.... did you find with the Knitters that you have to turn them pretty damn slowly to get KBEMUL to pick them all up properly? I put one on a scope, and it seems that it's a mechanical issue - if you turn them rapidly the contacts don't have time to make on each 'clickRichard

[Guest LeoL]

I really hope the dual-boot works out for you. Nice, sounds like you're using some kind of non-linear editing system. Real-time I bet. Do you use an AV SCSI drive for storing and playback?Knitters...As much as I appreciate your effort to get them for everyone that was interested, I simply don't use them. They have a serious problem with false signals and mechanically feel like I'm scraping something inside. Gives me goose bumps when I turn them. ;) They may be convenient in that they don't need a decoder circuit, but they simply don't compare IMHO to the Panasonic rotaries I use.Note - KB Studio has a setting to detect your turn rate in "Options" ->

[Guest LeoL]

I'll be helping Scott by generating the PCB and Gerber files for anyone interested in making his or her(?) own boards. As far as a USB version is concerned, I believe he's leaving that up to me, but my design will be completely different in nature than his.Richard, unless its a full-speed USB version (for which I

[Guest leonpo]

HiThere are two great articles in http://www.codeproject.com/csharp/csppleds.aspand http://www.codeproject.com/csharp/cspplcds.aspabout controling LED and LCD boards from parallel port.Leon

[rickalty]

Thanks, Leon

[Guest RichardL]

Leo,I've seen a few parallel port to USB adapter cables from different manufacturers at TigerDirect.http://www.tigerdirect.com/applications/ca...lc.asp?CatId=76Any idea if a parallel to usb cable could be used vs connecting directly to the parallel port?Richard

[Guest LeoL]

Richard,In theory, yes it should work with any hardware designed for PPT, in practice it might be a different story. What concerns me is their driver, which basically creates a virtual parallel port on your system.Anyone designing anything that uses the PPT needs a special freeware driver that gives access to the actual PPT hardware. Windows does not allow direct access to the PPT.So, the freeware driver has to be able to detect this virtual PPT created by the USB driver in order for everything to work. I would guess it would work since printers have their own printer drivers that do pretty much the same thing as the freeware driver, which is talk to the port hardware.The only other concern is the speed of the USB device they use. It may end up being slower than a direct connection to the PPT.Definitely something worth looking into once Scott finishes his design.-Leo

[Guest RichardL]

Thanks for the reply Leo. Might get an adapter cable a try. Richard

[Guest LeoL]

Richard, don't buy it!I just heard back from Scott and he has one. It doesn't work like a true parallel port as I had hoped. It has its own print manager utility and is strictly for printers. Won't work with any third party freeware PPT drivers so we have no way to talk to it.-Leo