a help on the circuit diagram for home automation control of lights,door and gate by using the parallel ports of a pc

 

Here's a place to start - http://www.beyondlogic.org/spp/parallel.htm.

You will need to select the sensing devices and decide how to interface them to the computer before you write the program.

 

It is better to use optoisolators between the parallel port and the devices you want to control as to avoid the possibility of destroyed the motherboard due to faulty external voltages.