December 12, 2024
I built a small Crystal Palace for an article I wrote for Nuts and Volts magazine in June of 2015. That version was controlled via Bluetooth because that was what I was experimenting with at the time. In that version the 1/4 inch acrylic rods were situated over an 8x8 LED matrix and the light from the LEDs illuminated the rods from below. It was small but also beautiful when viewed in the dark. Ever since that time I have wanted to go bigger, and now I have.
I built a small Crystal Palace for an article I wrote for Nuts and Volts magazine in June of 2015. That version was controlled via Bluetooth because that was what I was experimenting with at the time. In that version the 1/4 inch acrylic rods were situated over an 8x8 LED matrix and the light from the LEDs illuminated the rods from below. It was small but also beautiful when viewed in the dark. Ever since that time I have wanted to go bigger, and now I have.
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It consists of 37 acrylic rods ranging in size from 1/4 inch to 1 1/2 inches. The tallest rod extends about 14" above the case. The case, of course, was laser cut because all my new projects are. The rods are placed over a 5"x 5", 32 x 32 RGB matrix panel which is driven by a Raspberry Pi Zero W in conjunction with an Adafruit RGB Matrix Bonnet (#3211). A Passive Infrared Sensor (PIR) sensor, (the white bubble in the image at left), triggers the Crystal Palace to display a colorful lighting pattern whenever motion is detected. Currently there are over 40 unique lighting patterns coded into this Crystal Palace. Once triggered the pattern is displayed for 90 seconds extinguishing. However, every four minutes the Crystal Palace wakes up on its own just to make its presence known. The GForth programming language was used for the Crystal Palace. Why, you might ask, because I like to program in Forth. GForth is running on top of the Raspbian OS running on the Raspberry Pi. Yes, the Crystal Palace is running a multi-user, multi-tasking operating system. This works out well because I can access the Crystal Palace remotely. I don't need a physical connection to my computer to update and/or debug the code. Very convenient. |
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Each of the 37 acrylic rods had to cut to size and
both ends had to be polished. I used a blow torch to
melt the ends which worked for the most part but
professional polishing would have been better. As is,
the Crystal Palace is interesting to look at even when
not illuminated because of the cascading reflections
of the rods themselves. It is kind of mind bending.
The addition of colorful lighting enhances the effect
for sure. |
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A colorful view of the Crystal Palace in
operation. You can see the individual LEDs that are
illuminating the rods when you are looking down
towards the base. |
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Another colorful view. There are static lighting patterns that just display a single color to wildly fluctuating patterns that expand and contract over time. The Crystal Palace randomly picks the patterns to display and tries not to repeat the same patterns over and over. In other words, most if not all of the 40+ patterns will be displayed before they are repeated. |
Questions and comments to me Craig at: calhjh@gmail.com