Ok sorry to start a new thread on the same topic but it seems other people have had this problem too, and the other thread wasn't particularly on the topic of "how the hell do i get this thing to work!", but it kinda went that way anyway! The LCD in question is a 2x16 HD44780 generic screen from Maplin's. Hookay. I've wired up the LCD to the paralell port. Wiring is 100% correct, I've checked against several diagrams and its all fine. Power is from the 5V+ rail. When the machine boots, it shows the top line full back charachters, and the bottom is blank. When I try to send information to it, the screen goes completley blank. Nothing. Nada. And it stays this way until the next boot. I've tried using port95nt, and winio.dll for the port-driver, but neither of them seem to do anything. I'm pretty sure its a software problem. The thing is I've not actually seen how you're supposed to install these port-drivers. port95nt seems to just be an installer... which I presume works, and winio.dll i copied to the system32 dir. Do I need to register it or somthing? Anyway, has anyone had this same problem, and what was the solution?
What software do you use to actually run the LCD? The drivers you mention just enable software to work with it, but then you still need something like LCDC...
Oh yes, sorry. I've tried LCD studio, LCDC (but that doesnt work with paralell connections) and also the Winamp Plugin. All give the same results. Thus why I'm thinking its the port driver thats the problem.
I've checked my soldering so many times, and I'm totally sure its right. Completley sure. What makes me think that its software is someone else had this problem on a previously working module when they installed port95nt.
i cant really say, is it the right lcd type? I dont know much about lcds... so i cant really say... well.. wait ill get a link...http://forums.bit-tech.net/showthread.php?t=44604 might help ya
Yeah, like I said its a HD44780 compatible controller, genericy type screen. I'm pretty sure its the right type, its got the right number of input pins and everything. Manaul : http://www.maplin.co.uk/media/pdfs/N28AZ.pdf Maplin Page : http://www.maplin.co.uk/products/module.asp?CartID=040714214333533&moduleno=36389 Oh and I went through the FAQ... again.
Still not working eh? Try LCDInfo 0.6 beta, this one doesn't need any port driver. Select the HD44780 driver and configure / crosscheck the settings (pin layout) in the driver config dialogue.
I've found the best way to ensure your LCD is playing the game right is test run it on a 98 box first. In my experience there are less 'peculiarities' to rear their heads up, if you know what I mean Failing that, at least try another XP PC.
Well it sounds like it's wired correctly. Try using crystalcontrol software (from crystalfontz.com) to mess around as it supports HD44780's in addition to their own line of serial/usb displays.
Ok, in order! coorz - That program still gives me nothing I checked the wiring and it is exacly as it should be and still nothing LiL_MJ - unfortunatley this IBM PoS doesnt have any settings in Bios other than "on/off", so unfortunatley thats not an option On the other machine I tested it on though, had the same problem and none of the settings in BIOS made any difference malcom - unfortunatley I don't happen to have a 98 box knocking around here, so I can't really do that either. Firehed - I'm just gunna go download that software, see if I get anything out of it. Hmm, interesting. Vaary interesting. The screen seems to flicker, but with that Crystalfontz software, the test screen doesnt go away at all... it seems to be strobing but not displaying any data. Hmmmmmmm.....
Hmm... perhaps it's not the soldering job but actually a bad wire. Like it kinda got destoryed internally. You do have screens set up for it (crystalcontrol) right? Sounds better though... kinda. Also, check your control panel and make sure the transfer speed within crystalcontrol is the same as it's set for the parallel port, and make sure there aren't any jumpers or whatnot trying to make it run at a different speed.
In CrystalControl I'm trying to display windows version and windows build. The speed... I'm not sure about that as its set to "0" and there are no other options. As far as I can tell there are no jumpers relating to the paralell port at all. I did do a continuity check on the wires to make sure I had them in the right order, so I think they should be ok. In LCDInfo there is a "Slow HD44780" checkbox, but that doesnt seem to do anything either. I tried chaning the pins around and nothnig. Humm. I am slightly confused about the configuration in LCDInfo. It says "Notes for 4-bit mode. Connect D4-D7 of the LCD to D0-D3 of the LPT port" What on earth does that mean?
just one thng: how long is the parallellcable you are using? and how is the thing connected to ground? (grounded only on PSU,only on paralellport, or both?) The testpattern you get on startup is generated on startup i think, so it really only shows that the LCD gets power and is ok... Also: don't use the testpattern to set the contast after... it always get wrong (you can see the testpattern, but not the letters and so on...) tru turning the conrast pot for each new thing you try...
Yep all the test I've done ive moved the contrast through full 10k range. The module is grounded only through the PSU. The cable used to be about 2m long, but now its about 1m long (lots of stripping). The testpattern shows that its getting power ok, and that the controller isn't fried (probably isnt anyway :S) ... so that shouldnt be a problem. Should I connect the paralell port pins to ground?
yeah... http://www.myrolypoly.com/lcd_project/lcd_project.html go to this page and scroll down to the chematic posted there (i don't want to post the image directly, and i'm to lazy to host myself ) as you can see some of the pins are connected to ground... i don't know if it will help, but you could try... It could be some differences in the voltages there, making the signal levels to low... also: are you sure you havent connected everything on the D-sub connector mirrored?
Just looked at the CC settings... do you also have it set to 0x378 for the parallel port and the size set correctly? And check your bios, make sure parallel is enabled and set to 0x378. Those pins being grounded shouldn't matter... only about half of the schmatics I've read mention those and they're all a copy of that one anyways. In fact they're ground pins already so they really don't need to be connected to ground.
I have it set to 0x378 yes, checked that against the page on Device Manager, and it is correct (if XP is telling the truth anyway!) I'm fairly sure I've wiried it the right way around, as the connector im using has numbers next to the pins... but I'll check that anyway Thanks peeps
