In disc phyllotaxis, as in the sunflower and daisy, the mesh of spirals occurs in Fibonacci numbers because divergence (angle of succession in a single spiral arrangement) approaches the golden ratio. The shape of the spirals depends on the growth of the elements generated sequentially. In mature-disc phyllotaxis, when all the elements are the same size, the shape of the spirals is that of Fermat spirals—ideally. That is because Fermat's spiral traverses equal annuli in equal turns. The full model proposed by H Vogel in 1979 is
where θ is the angle, r is the radius or distance from the center, and n is the index number of the floret and c is a constant scaling factor. The angle 137.508° is the golden angle which is approximated by ratios of Fibonacci numbers.
Carefully turn the board over and solder only the middle pin of each header.
Ensure the headers are straight and level before proceeding to solder the remaining pins. The 5V and GND pins are connected to planes with large traces, and may take some time to heat up enough for solder to melt. Using a higher temperature and less time can help, if possible. Flux can also help.
Check each solder joint, then disconnect the female headers.
VERY carefully check polarity before connecting 5V and GND. If possible, connect 5V and GND on both sets of headers to provide maximum current flow and minimize voltage drop. I used female jumper wires.
Connect the data pin from your microcontroller to the DI pin on the Fibonacci board.
Each WS2812C-2020 can theoretically draw 5mA at full brightness, solid white color. 64 of them can theoretically draw 320mA. I suggest using FastLED’s power management to limit the maximum brightness to a reasonable amount, well under the maximum your power supply is rated for. I’ve found that 320mA is blindingly bright.
Keep an eye on the temperature of the PCB and especially the connectors. High temperatures can reduce the life of the LEDs. When possible, ensure air can flow, either passively (ventilation) or actively (exhaust fan).