An animated RGB LED graduation cap, running on a Raspberry Pi.
I like LEDs.
The assembled graduation cap is a 14x14 LED matrix of WS2812B NeoPixels driven by a Raspberry Pi. Patterns are selected using a prototyping board with several buttons connected to the Pi's GPIO. A breakaway connector is used to connect the two, improving portability.
Other projects like this exist with different materials. I chose NeoPixels since they are cheap and relatively easy to drive (in comparison to video walls). A Raspberry Pi was used since it's easy enough to work with, and if I had the time I could do fancy stuff like run a webserver.
Underneath the covers of the cap, the center is actually just cardboard. The LED strips that I used had an adhesive backing. I bought several meters of these strips, cut them into strips of 14, and stuck them onto the cardboard center. Because the signal of the NeoPixels are chained together, the strips are oriented in a zig-zag pattern. Soldering these strips together took some time, as the pads are somewhat fragile.
I've done a few projects with these LED strips before, like Internet-Xmas-Tree and PatioLightsHost. When developing these projects its always been difficult to quickly test that things are working on the actual hardware.
I built a simulator application using Tkinter to mimic the look of the hardware. This also encouraged a more modular design. It made the initial development a lot faster.
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Install the project dependencies:
python3 -m pip install -r requirements.txt
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Start the simulator:
python3 simulator.py
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Navigate through the patterns using
AandD.
Each pattern is in its own module, under pattern/.
These patterns are loaded by patternmanager. When new
patterns are added, they need to be added to the list of
all patterns in the patternmanager.
Each pattern must be a sub-class of Pattern.
The LEDs are driven by led.py, which runs as a background
service that starts when the Raspberry Pi boots.
The script has to be run as root for access to the GPIO.