Sunday, September 9, 2007

Build your own printer cable LCD Display Lcd كيفيه عمل كابل متصل بشاشه


Build your own printer cable LCD Display Lcd كيفيه عمل كابل متصل بشاشه

Connecting a LCD display to your personal computer is an easy job. Displaying data from your PC to a LCD can be proven very exiting, so give it a try and build your own today!
In this article we will use a 2 lines x 16 characters LCD display with Hitachi HD44780 onboard controller.

You can use any size of LCD like 1x16, 2x40, 4x20 e.t.c but keep in mind that it must have HD44780 or or compatible controller which is the most popular at this kind of LCD displays.

We will use a free printer port (LPT) for communication between LCD module and PC.

For this interconnection we only need 10 wires between LCD and LPT and two additional wires for power.

To control the LCD there are some free programs that can do that job very well and providing many capabilities. We will discover them later.


First of all let's see what parts you need:



A LCD display. This one is a 2x16 with HD44780 compatible chipset and backlight. The model number is SSC2B16DLYY. As you see in image we bought it 14.5 Euro.


Some male and female pin arrays. You need 16 if you have a LCD with backlight or 14 otherwise.

A printer cable. Can be found anywhere and it's cheap.



A Molex cable with additional cables at red (+5) and black (GND) to power with them the LCD. This is connected between an existing power cable and a pc's device.
Also you need soldering tools and pence. Assuming you have already this kind of tools





Unpack the LCD, and spend some minutes recognize it's parts.

This is the front side of the LCD module. You can clearly see the 1-16 pins, and the A and K pins (at the left of the image) that used if you want to power the backlight independently. We will not use them.

This is the back side of the LCD module. The two black circles you see are the controller chips. You can also see the 1-16 pins and the A and K pins.

Now take the male pin array

Cut 16 of them if you have a LCD with backlight or 14 otherwise.

Fit them at the back of the LCD

Turn over the LCD and solder the pins from the upper side.

Here you see the pin array soldered

Now take the female pin array and cut the same number of pins you cut before.





Mark the side you will use as the pin number 1

Take the side of the printer cable that goes to the printer and take it out from the plastic box.

Unsolder the wires
If you like you can use some heat shrink plasic to catch the wires together.

Use the schematic you see at the left to wire the female pin array so when it is fitted at the LCD the pins match correctly.

You may use two additional wires from that is not used to drive the power line to the other end of the cable that will be fitted to the parallel port.

Now desolder at the wires you will use for powering the LCD and attach another piece of wire to them, like you see at the right. This is the connector that goes to the LPT.

It should look like this when you close the plastic box.






Now it's time to connect it to the PC. The first thing you see is this at the image. This means that everything went right.

You have two chooses for the program that will control the LCD. First is LCD Smartie that can be downloaded from here. More info about this program can be found to the author's site.
This one has many abilities. The most common is to display the winamp song's Title, Lenght ect and the most rare is to fetch new from CNN's site and display them to your LCD.

And the second is the LCD Center

I both cases you will need the port95nt.exe which will give you access to the Parallel Port of your PC. You must also modify the Parallel port settings to EPP (sometimes ECP does work, but EPP is better) in your BIOS.

Below are some pictures from the LCD in action.

Saturday, September 8, 2007

The 8Way Relay Board دائره للتحكم ن طريق الكمبيوتر بالاجهزه المنزليه


The 8Way Relay Board دائره للتحكم ن طريق الكمبيوتر بالاجهزه المنزليه




This board is designed specifically to control the 5-motor Robot Arm sold by Baycom Technologies. It has no input facilities, but it is less expensive than combining the I/O Board with the Relay sub-Board. If you need lots of relays and no input, this is the way to go.










The 8-way Board with only 4 relays installed.

Parts List:

1 x PCB

8 x SPDT 12 volt Relays

1 x PCB mounted DB 25 Socket

1 x ULN2803 Integrated Circuit

1 x 1N4004 Diode

8 x 1N914 Diode

8 x 3mm Red LED

8 x 560 ohm 1/4 watt resistor

1 x 47uF Electrolytic Capacitor (up to 1000uF can be used depending on the power supply)

1 x 0.01uF (approx) Green Cap

1 x LM7812 Voltage regulator (T220 case)

1 x 1 amp Bridge Rectifier

1 x 2.1mm Power Socket

25 pin Serial Cable - Male to Male

12 - 24 volt power supply with 2.1mm Plug


Optional: 8 x 3way PCB mounted terminal mounts.

Kit Assembly:


Begin with the smaller items such as the 1N914 doides and then the IC. You can then start on the 'taller' items like LEDs, resistors, regulator, bridge, green cap, etc. Once you have the basic components soldered in, carefully install the DB25 socket. Make sure that none of the pins get bent over as you're trying to wiggle everything into place. It's a nightmare to unsolder the socket if you make a mistake! Leave the relays until last.