33 lines
1.4 KiB
Markdown
33 lines
1.4 KiB
Markdown
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# flame.ino
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This is a small arduino sketch to drive a string of WS2812 LEDs wound around
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a tube, to simulate a flaming torch.
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I have carried around the torch on various events and it has proven quite
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popular and served as inspiration for other similiar builds, see for example
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the work of Lukas, who expanded on the idea and added message scrolling:
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https://github.com/plan44/messagetorch
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This code is built for 5m LED strip with 64 led/m. The circumference of the
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tube is about 17-20 cm, so that after 12 leds one winding is complete.
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This is an arduino sketch, however, there are two small issues with this:
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It needs a patched Adafruit-Neopixel library, where I extended the
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constructor with a pointer to pre-allocated memory. That way I get some
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control on where in the memory the framebuffer is residing.
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Also, the memory in the arduino leonardo for 320 LEDs is tight. It tends
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to interfere with the bootloader activation since the "Catarina"
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Bootloader relies on some values in very specific memory locations to
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decide if it starts the main application or not. This value sometimes
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gets clobbered by the flame rendering code, in extreme cases it might be
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necessary to reflash your leonardo via ISP.
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I tried to keep the code clean and have the most important values as
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defines, so that it can be adjusted to different led layouts.
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Have fun!
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Simon
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