The mini-LCD screen
Thanks smartarse...
i know its not Bravo related, but i have done a guide for the LCD part of the project, that some of you may find interesting.
takes a deep breath...
You'll probably have to buy only three things to make your own printer-cable LCD: an 'Industry standard' LCD display with a Hitachi HD44780 (or compatible) chipset. (I got a 2x16 character display from maplins for £12. A standard printer cable to take the data output from your PC's printer port to the LCD screen and a Molex (HDD power cable) splitter/connector to power the LCD from your computer's power supply. Some wire and soldering tools are also required. While the soldering is a little delicate, it is not difficult. I will be the first to admit that my soldering skills are quite poor and if I can do this, then almost anyone can. A little practice and some patience is all it takes.
The bits
The first step (as you can see in the picture above) was to remove the plug-covers on the ends of the printer cable. Each cover had four little clips that could be opened to split the cover into two separate pieces. This allows you to easily identify which wires match the pins on the parallel port end of the cable.
A little bit of preparation can help quite a bit in a project like this one, and the next step was to 'tin' the contact points on the LCD's PCB. Simply place the bare solder wire over the contact, quickly push down with a hot soldering iron, and you should get a nice little blob of solder coating the contact.
It should look something like this
Next cut two pieces of wire - about 20cm longer than your printer cable - to take the power from the Molex connector to the LCD. Then cut three smaller lengths of black (or whatever colour your negative will be) wire and solder them onto the end of the longer piece - there are three negative/earthed contacts required, and only one positive (5V) connection.
Now the fun part begins - soldering the wires up the LCD - take it slowly and carefully and things should not be too hard.
Work with the Centronics (printer) end of the printer cable - because you'll want to plug the parallel port end into the back of your computer. Applying the soldering iron to the wires where they are soldered to the Centronics connector and pulling gently should be enough to undo the wires from the unwanted connector. Check the parallel port end of the cable to ensure that you are attaching the appropriate coloured wire to the LCD's PCB.
When you have finished wiring the nine printer cable wires to the PCB, it's just a matter of tidying up. First cut off the Centronics connector - the remaining wires are not required. Cut off any extra plastic bits and tidy the end of the cable up with some electrical tape and cable-ties. I also wound the two long power cables around the length of the printer cable and secured them with a fair number cable ties.
Like this
Connect the other end of the two power cables to your Molex adaptor - I cut off the 'floppy drive' connector and soldered the power wires into place. Make sure you use the red 5V line and not the yellow 12V line when wiring your LCD to the Molex connector. (Test the voltage of each of the rails with a multi-meter if you are unsure which to use).
Now that the cable is finished, it can be attached to the printer port on the back of your computer, and powered via a Molex connector from the inside of your computer case. When the computer is powered up, the LCD screen should - if working correctly - display a number of solid blocks.
..and thats about it..all that is left is to install the relevant software, you can use any but i found Crystal fontz to be the best. It's very easy to configure and use.
Phew...
Daz
