Creating a mood lamp

Lighting is one of the biggest opportunities for homeowners to effectively influence the ambience of their home, whether for comfort and convenience or to set the mood for guests. In this section, we will make a simple yet effective mood lamp using our own Arduino. We will be using an RGB LED for creating our mood lamp. An RGB (red, green, and blue) LED has all three LEDs in one single package, so we don't need to use three different LEDs for getting different colors. Also, by mixing the values, we can simulate many colors using some sophisticated programming. It is said that, we can produce 16.7 million different colors.

Using an RGB LED

An RGB LED is simply three LEDs crammed into a single package. An RGB LED has four pins. Out of these four pins, one pin is the cathode (ground). As an RGB LED has all other three pins shorted with each other, it is also called a common anode RGB LED:

Here, the longer head is the cathode, which is connected with ground, and the other three...