This little tree uses an Arduino with an Ethernet Shield to track the Cheerlights channel on ThingSpeak. Cheerlights allows lights around the world to be controlled in unison via Twitter. This tree is nothing more than 10 RGB (red/green/blue) LEDs connected in parallel to an Arduino with an Ethernet Shield running a modified version of the cheer lights sketch.
: arduino uno, ehternet shield, leds
Wire up the Test Schematic (below)
- Plug the RGB LED into your breadboard
- Connect a current limiting resistor to each of the three cathodes
- Connect the common anode to 5V (5 volts)
- Test each color by connecting its current limiting resistor to ground (GND)
- Experiment with colour mixing a little by powering multiple elements at once
Arduino Controlled Example Circuit
There are two ways to do this. For the more advanced consult the schematic below.
Digital Control of Color
It is possible to control an RGB LED digitally. This requires 3 digital pins for each LED and allows for 7 colours to be displayed (Red, Green, Blue, Yellow, Cyan, Magenta, White).
Analog Control of Color
Now onto the fun stuff, controlling an RGB LED using the Arduinos PWM (pulse width modulation) pins. This lets you create almost any colour your heart desires, and better than that fade between colours.