Build Your Own LCD

Build Your Own LCD
Posted :: Jul 19, 2004 by Impact

Difficulty :: 7/10
Skills :: Soldering
Tools :: Soldering Pencil (Iron), Wire Cutters/Strippers, Needle-Nosed Pliers.
Parts :: HD44780 LCD, Parallel Cable, Molex Connector

Ever wonder how people make those LCD that sit in the front of your case? Don't wonder any more, in this tutorial you will learn how to wire a 16x2 HD-44780 (most common) LCD to your current computer.

First, if you don't have a HD-44780 Compliant LCD, go get one. You can grab them for $8-10 on ebay. Second, go get a parallel cable, you can find a parallel cable at any electronics store. They were used in a lot of old printers, so if you have an old printer, you might already have one. You will also need a molex connector (Male metal pins) that you can plug into a power source on your computer. If you don't have anything you can rip apart to get one, go to an electronics store and buy a 4-pin Molex extender.

If you are good at soldering, this is quite an easy mod. Cut off the female side (Female metal pins) so you have a male side with long wires attached. Then strip the plastic coding off of the end of the parallel cable, to make this clear: Cut the side that doesn't attach to the computer. Instead of using the names of the sides, figure out which side of the parallel cable attaches to the computer, and use the other side... Use the following list to guide which wires go where. (Colors may not be correct, so use the pin numbers as the main reference)
LCD Pin: Wire to attach
1: Ground (Black wire on Molex connector)
2: +5V (Red wire on Molex connector)
3: Ground (Black wire on Molex connector)
4: Parallel Port pin 16 (Green/white wire)
5: Ground (Black wire on Molex connector)
6: Parallel Port pin 1 (Pink wire)
7: Parallel Port pin 2 (Red wire)
8: Parallel Port pin 3 (Yellow wire)
9: Parallel Port pin 4 (Green wire)
10: Parallel Port pin 5 (White wire)
11: Parallel Port pin 6 (Blue wire)
12: Parallel Port pin 7 (Purple wire)
13: Parallel Port pin 8 (Pink wire)
14: Parallel Port pin 9 (Grey wire)

As with any soldering, be careful and make sure that none of the solder points (or excess bare wires) are touching each other. Once sure, I put electrical tape all over mine, this was for three reasons: 1) It made it look nice. 2) I didn't have to worry about the solder points touching any other wires, or my case and shorting out. 3) It prevented my wires from moving very much, the wires are so tiny that some movement might make them snap.

Unfortunatly I have no pictures of my LCD being soldered. I do have final pictures. If you need more help on the soldering part, feel free to ask questions.

My completed LCD mod. The two wires on the left are going to my molex connector (not pictured).

If you want to be fancy, you can attach a 10k potentiometer to the 3rd LCD pin. This will allow you to vary the amount of contrast. I didn't include this in the main guide because I leave mine turned 100% the entire time. I wish I had just connected the black wire as the pot makes it much more bulky.

My LCD with the potentiometer shown. I never change the setting on mine, I suggest you just short the 3rd LCD pin with the black wire as described above.

Once you have the LCD built, its time to hook it up. There are many programs available for driving HD44780 LCDs through a parallel connection. I tested a few and found my favorite to by CrystalFontz CrystalControl. CrystalControl can be downloaded from:
http://www.crystalfontz.com/software/crystalcontrol/
Note: Although it is a serial/USB control program, if you read down the page, it says it supports HD44780s through parallel. I have used it on mine for a year, works fine.

The software is very easy to work with, and will interface with Winamp and MotherboardMonitor easily. Just set what you want displayed and go!

A shot of mine in action about 20 min after completing the mod. This time it is showing the temps and speed of my chip.

Another shot, this time showing stats from winamp.

Although I didn't put mine in the front of my case, that is an ideal place for it. Cut a hole in a drive bay cover and screw/bolt the LCD in place. Then run the wire through the case, out the back, and into the parallel port.