Code examples for the RGB Xmas Tree

Start by downloading the xmas tree file. Open a terminal and type:

wget https://bit.ly/2Lr9CT3 -O tree.py

Test the tree by running python3 tree.py (or running it from an IDE like Mu, Thonny or IDLE). All the lights should come on (white).

When you write your own Python code, make sure you keep this file in the same folder.

If you're using Raspbian Desktop, you don't need to install anything. If you're using Raspbian Lite, you'll need to install gpiozero with:

sudo apt install python3-gpiozero

Open a Python shell or IDE, import RGBXmasTree and initialise your tree:

from tree import RGBXmasTree

tree = RGBXmasTree()

You can set the colour of all the LEDs together using RGB values (all 0-1):

from tree import RGBXmasTree

tree = RGBXmasTree()

tree.color = (1, 0, 0)

Alternatively you can use the colorzero library:

from tree import RGBXmasTree
from colorzero import Color

tree = RGBXmasTree()

tree.color = Color('red')

You can write a loop to repeatedly cycle through red, green and blue:

from tree import RGBXmasTree
from time import sleep

tree = RGBXmasTree()

colors = [(1, 0, 0), (0, 1, 0), (0, 0, 1)]

for color in colors:
    tree.color = color
    sleep(1)

You can also control each LED individually, for example turn each one red, one at a time:

from tree import RGBXmasTree
from time import sleep

tree = RGBXmasTree()

for pixel in tree:
    pixel.color = (1, 0, 0)
    sleep(1)

To control a specific pixel, you can access it by its index number (0-24):

tree[0].color = (0, 1, 0)

You can change the brightness from 0 to 1 - the default is 0.5. You can set this when initialising your tree:

from tree import RGBXmasTree

tree = RGBXmasTree(brightness=0.1)

Alternatively, you can change it after initialisation:

from tree import RGBXmasTree

tree = RGBXmasTree()

tree.brightness = 0.1

You'll find that 1 is extremely bright and even 0.1 is plenty bright enough if the tree is on your desk :)

Cycle through red, green and blue, changing all pixels together

• rgb.py

Cycle through red, green and blue, changing pixel-by-pixel

• onebyone.py

Cycle through hues forever

• huecycle.py

Randomly sparkle all the pixels

• randomsparkles.py