How to output an Infrared LED?

How do I code an output Infrared LED?

What is it doing?

I am making a project where if I block the IR led from the IR receiver, it will sense it.

Its for my class project. When it senses that my hand is between the receiver and led, a 2 minute countdown starts.

Depends on whether there is a lot of background light - if so then you may need to modulate the
LED and use a band-pass filtered receiver to ignore the background. This is how remote controls
work, there are examples if you search.

If background light not an issue then just pass the design current continuously through it with a
series resistor. If its a high current LED then a transistor may be needed - if its 20mA then you
can drive from an OUTPUT pin without the transistor (but don't forget the current limit resistor).

Background light will be an issue. Do i have to use the IR library or is there some code that can output a specific frequency and can make the receiver look for that specific frequency. Can you please list some links in order to push me in the right direction? I have been surfing the web for answers for the last hour or so.... Thanks!