How to connect 12 LEDs to the computer's parallel port (LPT)


Facilities for LED

Circuit diagram

Panel example


BIOS settings

^ Facilities for LED

At first, you need 1 led.

The red LED


Find LPT port on your motherboard. Look for pin's labels.


LPT connector. How to locate labels


Check numbers.


LPT Pins and numbers


Join LED to pin 2 and 18.


LED directly on LPT


Now You can use WndLpt to control this LED.


Flashing LED in LPT socket


^ Circuit diagram for 12 LEDs

You can directly connect up to 12 LEDs to the LPT port. It's very simple.

Some people prefer to connect only 8 LEDs. It's not a problem. The WndLpt program can manage any quantity of LEDs from 1 to 12.


It's time to make the following circuit. You can see a face of motherboard's LPT port or DB25F Face (or DB25M Back side) on it.

click to enlarge

Circuit - How to connect 12 LEDs to the computer's parallel port (LPT)


The same circuit is made otherwise.


Old circuit

^ LEDs panel example

It is a good day to mount the LEDs to the panel.

You can take any dark plastic plate and drill 12 holes along a circle.


12 LEDs panel example


You have got the following view.


LEDs Panel Photos in the night

^ Photo session



Hole for LED

LED in the hole


Panel with 12 LEDs, front side.


LEDs panel, face


Back side of this panel.


LEDs panel, back


Map-circuit to the panel.


Mapped panel


How You can fix the led.


Fixing LEDs


DB-25M Connector


Switchplug DB-25M


DP-25C case for DB-25M


Case DP-25C for DB25M


Connection of DP-25C with DB-25M


Join DB-25M and DP-25C


Male connector for LPT port (DP-25C and DB-25M)


Switchplug DB-25M + DP-25C


LEDs in the night

Easy effect

^ BIOS settings — only if LEDs glow with low brightness level

Enter to the BIOS. Set this parameters:


[Integrated Peripherals]

Onboard Parallel Port = Enabled or 0x378h

Parallel Port Mode = EPP


Select Save & Exit Setup and press Y.