I dont understand exactly what you are talking about here.
i have little knowledge of computer. Can i use parallel port or serial port? which is better to use?
thanks..
For you, a parallel port may be the best. It outputs a byte (8 bits) at a time, and the strobe temporarily enters a logic low state when a new byte is on the line. Make your project accept the parallel format and you should be ok. DONT go over 5V with the port.
As for serial port, it is less bulky, BUT it is harder to use because you are dealing with start and stop bits, PLUS you need to include a timer in your circuit which is the same speed as the serial port data to avoid miscommunication.