i need turbo c program for controlling led's using push buttons or switches..

[doyan]

this is the given problem...

If switch 1 is pressed then led's will light alternately from left to right..
If switch 2 is pressed then led's will light alternately from right to left...

this is connected to parallel ports...
please help me...

[code green]

This is an electronics problem.
You need to get the circuitry right first and make it work mechanically.
Then replace the mechanical switches with relays.

[donbock]

How many LEDs?
How are the LEDs connected to the computer?
When you say "will light alternately", do you mean there is never more than one LED lit at a time or do you mean that all of the LEDs turn on one after the other?
How much time should elapse between each change in LED state?

[doyan]

there are 4 LEDs...
LEDs are connected through a parallel port...
it will light one at time.....exampl e... led 1 will light,then 2,3,4..then after that it will light light from 4, then 3,2,1...if led 1 will light,2,3,4 are off...if led 2 will light 1,3,4 are off and so on...
there should be 1 second interval...

please i need it badly...

[code green]

A quick google found this project

http://www.codeproject.com/KB/cs/csppleds.aspx

[doyan]

@code green...sir,i find that link very useful but i don't know how to make a program that would fit my problem which is making light on from left to right and right to left...
could you help me make the program?

please??

[doyan]

could you help make a program about LED connected to parallel port..

4 LED's will light from left to right if switch 1 is pressed and it will light again from right to left if switch 2 is pressed...

should have 1 sec elapse/interval time....

please?
Forward Message

[code green]

The algorithm is to have an array of port addresses corresponding to the LED connections of the parallel port.

Poll the switches looking for a message
{
 Loop through the array
 {
    Send address low (switch off)
 }

 Check which switch is pressed then loop through the array
 either forwards or backwards
 {
    Send the port address high.
    Delay a second or so.
 }

}

[donbock]

Start with the basics. Do you know how to manipulate the parallel port to light a single LED?

Create a subroutine that lights whichever LED is specified by the argument. Then create two additional subroutines: one that sequentially lights the LEDs from left to right; and one that sequentially lights the LEDs from right to left. Finally, write a main program that decides when to call each of those sequential-LED functions.