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3D RGB Xmas Tree Light Chaser

How are you getting on experimenting with your Raspberry Pi 3D RGB Xmas Tree? You can create some cool effects with the LEDs and minimal coding. I’ve been experimenting with mine, and wanted to create a tree chaser light effect so the lights appear from the bottom, before this can happen I needed a map in the order of which the LEDS light up.

I used a simple program to simply set tree[index].colour = 1, 1, 1 where index = 0 – 24, and that resulted in the map below. you can print it out and stick them together to create a more visual map of the lights.

Updating the modified program from I’ve added a simple list of the order of LEDs and amended the code that updates the colours from a PNG file.

# Pattern List of the order of LED Light on the RGB Xmas Tree
# Starting from Front Left, working around the tree anti-clockwise
# Be Creative, create light chasers!
XMASLEDLIST = [7, 20, 25, 1, 8, 16, 17, 13,     # Bottom Row
               6, 21, 24, 2, 9, 15, 18, 12,     # Middle Row
               5, 22, 23, 3, 10, 14, 19, 11,    # Top Row

and modified the main loop

                for index in XMASLEDLIST:
                    offset_x = (x * channels) % (pattern_w * channels)
                    r, g, b = row[offset_x:offset_x + 3]
                    tree[index-1].color = r/255.0, g/255.0, b/255.0
                    offset_y = int(delta % pattern_h)
                    row = pattern[offset_y]

If you want to run the code in Debug and see the lights switch on individually add tree.update() before the delta+=DELTA_OFFSET and set your breakpoint on the delta+= line of code.

If you want to grab the latest code, you can go to or clone the repository using git.

git clone

Happy Pi’ing and Here’s to a much better 2021.


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