Arduino + 4 pin 5mm Full-Color LED

• Remember, the longest pin of the LED is the anode, the other three short pins are the cathodes (RGB)
• Also, while the flat side of the transistor is facing you, the left pin is the collector, the middle is the base, and the right pin is the emitter.
• The photo notes the 2N2222 transistor. For the 2N3904 and 2N4401, the Collector and Emitter are switched.

• Connect the LED to the breadboard.
• Connect the anode of the LED to the other half of the breadboard.
• Connect the cathode (frist pin) to the other side of the breadboard.

• Connect the collector of one transistor to the first cathode of the LED.
• Connect the other transistors as shown in the image. Connect the collector of the second transistor to the second cathode of the LED.
• Connect the collector of the third transistor to the third cathode of the LED.
• I'm using the 2N2222 transistor, so in my case the transistor faces my direction. If the 2N3904 or 2N4401 transistor are used, the transistor will face the opposite direction.

• Connect one resistor to the base of the third transistor.
• Connect the second resistor to the base of the second transistor.
• Connect the third resistor to the base of the first transistor.

Connect the emitter of all three transistors to ground.

• Connect the resistor from the third transistor to pin 9 on the Arduino.
• Connect the resistor from the second transistor to pin 10 on the Arduino.
• Connect the resistor from the first transistor to pin 11 on the Arduino.

• Connect the anode of the LED to pin 12 on the Arduino.
• Connect ground from the Arduino to the ground strip of the breadboard.

• Connect your Arduino to your computer (running Windows, OSX, Linux).
• Open the Arduino program and upload the Arduino code within the following images.

• After uploading the code, open the serial monitor and input a character from 1 - 8.
• 1 = RED, 2 = GREEN, 3 = BLUE
• The LED only has three pins for RGB (Red, Green, Blue), but turning on more then one pin creates diverse colors.
• 4 = PURPLE, 5 = AQUA, 6 = ORANGE, 7 = BRIGHT WHITISH PURPLE
• 8 = OFF

Normal RGB light settings.

Other RGB settings. RB, GB, or RG.

All RGB cathodes on or off.