christmaslights

I made a Christmas tree with addressable lights, similar to what Matt Parker (Stand-up Maths) did. His tree can be viewed on Youtube and his code is on Github as well.

I was inspired by his code, but I set out to write my own code to map the LEDs to their 3d coordinates. This repository contains the tools that I wrote to do so, as well some code for driving the leds.

I documented my progress on my blog: http://blog.jasperhorn.nl/search/label/christmas%20tree

Sub-projects

• onedimensional

  Some code that drives the LEDs normally, based on their position in the cord

• mapper

  The code I used to assign coordinates to the LEDs

• threedimensional

  Some code that uses the coordinates to drive the LEDs in 3d space

Installation

Each project contains its own requirements.txt file, which can be used by pip to install any and all requirements. It is of course advised to do this in a virtual environment.

Additionally, the mapper project required a non-python dependency (sdl2). It is listed in nonpython-requirements.txt in the form of an apt-get command which should work on Raspberry Pi OS.

Running the code

The library to control the LEDs needs root access. However, python virtual environments do not work nicely while running as root out of the box. That's why each of the projects contains a sudopython file. You can use this as you would use sudo python (e.g. ./sudopython main.py). However, it adds the bits that make it run in the virtual environment you're currently in.

Usage

onedimensional

./sudopython main.py off: turn all leds off

./sudopython main.py one: make the first led red (and all others off)

./sudopython main.py randomize: one by one, randomize the colors of all leds

./sudopython main.py moving-dot: Have one pixel move through the leds

./sudopython main.py fill: one by one, turn on all leds

./sudopython main.py gradual: a gradient effect that moves back and forth

./sudopython main.py rainbow: a rainbow effect that moves through the leds

./sudopython main.py white: make all leds white

./sudopython main.py repeat-white: continuously make all leds white (so newly connected ones are made white too)

mapper

config.py contains config such as the number of LEDs and camera resolution, so you should modify this to fit your situation.

./sudopython frame.py: takes a picture (saved to output/photo.jpg) which you can use to get the tree nicely in frame

./sudopython mapper.py: start the mapping process. It will print out instructions, so just follow those. For best results, do the mapping in the dark (you can turn on the lights when it tells you to rotate the tree, as long as you turn them off again before pressing afterwards)

./sudopython verifier.py: start a process to identify LEDs with incorrect coordinates

./sudopython mapper.py fix: rescan LEDs with incorrect coordinates (uses the output from the verifier)

`./sudopython identify.py n: light up the LED with index n up in green and any following indexes in blue. This can help identify LEDs if you need to map some of them by hand

threedimensional

coords.txt is the coordinate mapping and should be copied from mapper/output/coords.txt

./sudopython test.py: A simple test script that just changes colors in one of the direction of the y axis

./sudopython test.pyi x: Run the test for the x axis

./sudopython test.py y: Run the test for the y axis (equivalent to leaving out the y)

./sudopython test.py z: Run the test for the z axis

./sudopython off.py: turn all LEDs off