I have LCDs but Im stuck

hungry joe · 04-20-2004, 03:32 AM

Hi there. I have recently come into possession of 2 NEC NL6448ac20-06 LCD displays (specs TTL interface I think...) which are attached to CoCom Voyager 2 embedded Mobo's (google for them if interested), which have TTL interfaces.

Unfortunately I didn't have any mains adapters for these so I may have blown one of the mobos, by progressivly putting more power in until something happened (at 7v 2.1A BIOS started booting then it turned off and now it just beeps instead. I think the LCDs are OK). This isn't such a problem as I don't care about the mobos much anyway, but I was wondering if anyone knew somewhere I could get a cheap mobo that I could use to make a touchscreen mp3 hifi that would work with these LCDs. None of the boards at mini-itx.co.uk have TTL connectors. Should I just sell them on ebay.co.uk? How much would I get?

Rob Withey · 04-20-2004, 04:07 AM

A standard parallel ports kick out TTL levels. That's what I use to drive my VFD.

hungry joe · 04-20-2004, 02:41 PM

actually Im not even sure if it is TTL. Its a 640x480 screen, surely that can't run off a parallel port?

Rob Withey · 04-20-2004, 02:51 PM

Read this thread. It refers to the exact same LCD. Geez, someone must be selling a job lot of these things.

http://www.mp3car.com/vbulletin/lcd-display/24783-precautions-wiring-up-lcd.html

siberia37 · 04-20-2004, 02:53 PM

Quote: Originally Posted by hungry joe

Hi there. I have recently come into possession of 2 NEC NL6448ac20-06 LCD displays (specs TTL interface I think...) which are attached to CoCom Voyager 2 embedded Mobo's (google for them if interested), which have TTL interfaces.

Unfortunately I didn't have any mains adapters for these so I may have blown one of the mobos, by progressivly putting more power in until something happened (at 7v 2.1A BIOS started booting then it turned off and now it just beeps instead. I think the LCDs are OK). This isn't such a problem as I don't care about the mobos much anyway, but I was wondering if anyone knew somewhere I could get a cheap mobo that I could use to make a touchscreen mp3 hifi that would work with these LCDs. None of the boards at mini-itx.co.uk have TTL connectors. Should I just sell them on ebay.co.uk? How much would I get?

Looking at the specs it looks like TTL yes but there's 31 pins in the interface- 7 more than a DB25 parallel port has. To get them to work over serial or parallel you'd probably have to make some kind of PIC circuit that would translate serial commands to actions on the LCD- pretty complex stuff but it could be done. Actually, I take that back- maybe you can use the 4-bit mode connection diagram and hook that up to a parallel port- but you are still stuck doing custom software programming most likely and any software would take a huge amount of CPU to reproduce the timing correctly. In other words.. good luck.

awh4992 · 04-20-2004, 03:04 PM

i didn't look to c how fast and whatnot the mobo is you blew out, however, the board i use has a tft lcd connector on it. i'm using an lcd right now that is pin for pin compatible w/ the nec display you have. also, i'd seriously doubt u'd be able 2 drive that lcd off the parallel port and expect to be able to use all 256k colors. anyways, the board i have is an arcom sbc-gxm embedded board. it runs entirely off 5v, and draws about 1A w/ full cpu usage (i'm not including the LCD inverter power consumption here). it's only got a cyrix media gx (AMD/national geode) runnin @ 233mhz. so...its kinda slow, and u won't be able 2 play movies on it. but its still pretty sweet cause its got a touchscreen controller built on, pc104, and pc104 plus bus on it (ISA and PCI busses). there were a bunch of those boards on ebay, but who knows if they're still there or not. the board supposedly supports a number of different displays, but u need different bioses which arcon doesn't seem 2 wanna give out if u don't buy the board from them. oh well, ur display is natively supported. the only trouble u'll have is finding a mating connector for their retarted lcd connector. that connector isn't made anymore, and the replacement one isn't stocked by mouser, digikey, or allied electronics. i don't think newark had it either. i hacked the connector to accept a 68pin scsi connector. what fun. so ya i hope this helps ya some. andy