Timer

I have looking for the best way to add a timer to my sketch without
using delays

I want a timer run for 15 secs when a digital pin is switched to ground
and then run a simple code to ground another pin ( Switch HIGH )

I found "simple timer" which looks good but I cannot get the timer to do this
It looks like the timer starts its count from the boot up and not when i want

Is there a simple code to do this function?

Show us the work you have done so far.

After 40 posts you must have come across BWD blink without delay techniques.

.

I want a timer run for 15 secs when a digital pin is switched to ground
and then run a simple code to ground another pin ( Switch HIGH )

You don't need a timer for that. Think about how YOU would perform the task if the time scale were 15 minutes, instead. You'd note when the trigger event happened. Periodically, you'd see if now minus then exceeded the required time. If so, you'd perform some action.

That is exactly what the blink without delay example illustrates.

Thanks Guys ive got it now

The demo Several Things at a Time is an extended example of BWoD.

...R