You are now going try a more advanced method of controlling LEDs. So far, you have simply turned the LED on or off. Would you like to adjust the brightness of an LED? Can you do that with an Arduino? Yes, you can.
Time to go back to basics.
Green Diffused 5mm LED
Current Limiting Resistor
The circuit for this project is simply a green LED connecting, via a current limiting resistor, between ground and Digital Pin 11 (see Figure 3-3).
Figure 3-3. The circuit for Project ...