Kyle France: Everything Working

The project is coming together, but still a lot of polishing to be done. I haven’t been able to get time on a laser cutter to make the final cuts on my acrylic, and I am still deciding on a centerpiece. Aside from these two finishing details, I have created a replica of the final structure in cardboard with all of the final lighting installed. The overall piece has shrunk some from the maquette due to my previous problems breaking the acrylic.

I had some difficulty with wiring and control when I switched from three LED’s to a neopixel 60 pixel strip and an 8 pixel stick. The strip requires its own power supply, which introduced a ground loop and strange noise into my circuit, and I needed to integrate the Adafruit neopixel library. I also adjusted the filtering to separate the signal into bass and everything but bass, which I think will give the best visual effect. Below is a rough diagram following the flow of the circuit and arduino code, from audio jack to LED’s. It is accompanied by a plot of different signals.

The averages (Avg) shown are actually moving averages with an adjustable weighting for the newest signal point versus recent signal values. This allows me to use information about how far the signal is from average instead of a raw volume value. This is much cleaner visually and automatically scales to different average volumes of songs. I’d like to thank Ryan Johnson for providing and explaining this section of code.

Above is a snapshot of the arduino serial plotter, showing the audio input (green), the first average value (yellow), the output to the “All” channel (blue), and the output to the “Bass” channel (orange). Overall, I’m glad the audio signal processing is done… Random things such as power supply noise or loose connections massively distort signals and are hard to troubleshoot. The lights are finally beginning to dance as intended!

Here at last is the full draft, so to speak. The base plate and backdrop will be replaced with acrylic, and the light strip will be mounted with more careful control of where light is directed. I am thinking the center piece will be another panel of acrylic with an etching of a car, as per an excellent peer suggestion. While the sun and the surrounding part of the backdrop will have to be one panel, I am going to try to address the strip LED’s individually to make the sun a different color.

Leave a Reply