[hanleychan]

Hi,
I recently bought this and received it in the mail today
http://cgi.ebay.ca/ws/eBayISAPI.dll?...EBWN%3AIT&rd=1

I have no idea how to connect this to the computer at all. Don't even know where to start. The seller told me that I could connect it but I had to make my own cable. Does anyone know if there are some very simple step by step guides on how to do this.

thanks

[Serraph]

Here are some LCD links:

http://forums.bit-tech.net/showthread.php?threadid=5582
http://www.gideontech.com/guides/lcd/
http://www.overclockers.com.au/~mwp...tup-hd44780.htm
http://www.icehw.net/article.asp?id=104
http://www.overclockers.com.au/techstuff/a_diy_lcd/
http://www.myrolypoly.com/lcd_project/lcd_project.html

The circuit design may differ slightly depending on 1) if you want to use potentiometers to control contrast/backlight 2) if you want a fixed level of contrast/backlight 3) if the lcd has a backlight at all 4) etc

It's pretty easy to do actually. All you're really doing is soldering the wires from the lcd pins to the db25 printer cable.

For the software:
http://www.crystalfontz.com/softwar...trol/index.html (free and easy to use; can display MBM5 and other computer info)

http://www.lcdc.cc/index.php ($17.50; alot more functionality than CC)

http://jalcds.de (my favorite, not recommended for beginners)

[hanleychan]

Basically from what I read am I susposed to cut off the centronics end of the printer cable and connect pins 1 to 14 on the lcd to the correct wires on the printer cable. Then connect pins 15 and 16 to a molex connector for the backlit power?

[Cyrix_2k]

Originally posted by hanleychan
Basically from what I read am I susposed to cut off the centronics end of the printer cable and connect pins 1 to 14 on the lcd to the correct wires on the printer cable. Then connect pins 15 and 16 to a molex connector for the backlit power?

You got it Just be careful with the power. EL backlight require an inverter while LED backlights usually require a resistor.

Also, before you plug it in, check all connections for continuity with multimeter.

[Serraph]

Originally posted by hanleychan
Basically from what I read am I susposed to cut off the centronics end of the printer cable and connect pins 1 to 14 on the lcd to the correct wires on the printer cable. Then connect pins 15 and 16 to a molex connector for the backlit power?

That or you could just buy some wire and make your own cable. I could never find one of those older printer cables that could be taken apart so I just wired my own up and used heatshrink to contain the wires.

Here's links for the connector and housing:
http://www.jameco.com/cgi-bin/ncomme...nbr=501&ctgys=
http://www.jameco.com/cgi-bin/ncomme...nbr=501&ctgys=

[hanleychan]

Yeah I couldn't find any printer cables like that ethier. I looked at future shop, staples, and radio shack and all they seem to have are the cables with molded connectors

[{BC}Helix]

you should look at your local electronics shop, if you have soldering skills you can just buy a blank male connector for the parallel port and solder your wires onto that. here are some pics of the way i did it that might help you hook your's up or give you some ideas. I followed the guide over at gideontech http://www.gideontech.com/guides/lcd/
you can see how i hooked it up to my power supply too.

[hanleychan]

based on the table from http://www.myrolypoly.com/lcd_project/lcd_project.html it says that pin 15 and 16 are for led + and led - for the backlight. I was thinking of using a molex connector from a case fan would this work? Also which wire is the negative and positive (red or black)

thanks

[{BC}Helix]

yes, and a molex power connector for +5 and -ground would work. Red is + and Black is -

[hanleychan]

Got a problem. For some reason after I connect the lcd to the parralel printer port it doesn't seem to work. I get no picture on the lcd. I soldered the wires from the printer cable directly to the lcd. The led seems to work though when I plug in the power from my power supply. Could it be a contrast problem? I am pretty sure I got the connections right because I checked it over. I think pin number 3 on the lcd is for contrast adjustment but the table leaves out pin number 3. What should I do?

I am using this table
DB25 connector Pin Number LCD Pin Number LCD Pin Description
1 6 Enable
2 7 Data 0
3 8 Data 1
4 9 Data 2
5 10 Data 3
6 11 Data 4
7 12 Data 5
8 13 Data 6
9 14 Data 7
14 5 Read/Write
16 4 RS
25 1 Ground
13 2 +5V

[hanleychan]

nvm. Never read the instructions properly. I'm susposed to connect a wire from pins 3 to 1 on the lcd to fix the contrast. Can I use anywire to do this like speaker wire?

[hanleychan]

I need help again. I don't know what to do. I soldered everything from that tablle onto the lcd and connected pins 1 and 3 together and it still doesn't work

[{BC}Helix]

i think you need to put in a potentiometer to vary the contrast, (you can also put one in for brightness too). what guide did you follow? I suggest you look at this schematic and see what you could have done wrong with your wiring.

[hanleychan]

I was looking at this one
http://www.overclockers.com.au/~mwp/...up-hd44780.htm

it says that I can solder a wire from pin 1 to 3 to fix the contrast.
I tried attaching a molex connector to pins one and two on the lcd. red on 2 and black on 1 and it seems to show the first and 2nd column all filled with black squares. This is good or not?

[{BC}Helix]

yes! thats exactly what you want to happen, two lines of squares. All you need to do now if find a program to power the LCD

[hanleychan]

I connected everything and powered on the computer. There was a spark on a wire near the lcd that scared the living crap out of me then the computer shut it self off. I was so scared that I fried the whole computer because I could power the computer on for a while after this. It seems to work now though. I don't think I shorted the lcd becuase it still shows the 2 rows of filled squares when I power it on and the backlight still seems to work. Wierd.

[shard]

dont worry it probaly it just was some condensation on the link

[hanleychan]

I plugged everything in and it shows the 1st and 3rd line of the boxes filled in, but its not working properly with the programs. I am trying to use this program

http://www.crystalfontz.com/software...rol/index.html

the stuff don't display properly. All i get are some boxes that are filled completely in black. Have I damaged my lcd?

[hanleychan]

Heres some of the gibberish that its displaying when I use that program to display the date and hd space
http://members.shaw.ca/hanleychan/lcd.JPG

I hope I didn't break my lcd

[{BC}Helix]

hmmm, thats odd. you might want to try a different program. the one i use is called JALCDS if you use that you're going to have to get a file file called DLPORTIO.DLL, you can find it if you search on google. anothing thing might be your baud rate. can you find anything if that program about that?

edit: also check what setting your parallel port is at in the BIOS