the Moon Clock

Here's my panel layout.  I print this (after further processing) on my CNC foil-punch, but that's a different story.  The scale is such that the adafruit.com "dotstars" will fit.  The dotstars are spaced at 1.666cm.  That magic value is the center-to-center spacing of the two "side" segments within one of the digits in the alphanumeric display; it's also the spacing between side segments of adjacent digits.  The digits are four times this value tall. The overall unit fits nicely in readily-available 8x10inch "shadow boxes", available from Mr. Internet.  These are like picture frames with deeper boxes, usually about 1+1/2" depth.  These most often have glass front panels, but I seek out ones with plastic ("Lexan" or similar), and I highly recommend these: because this makes them much easier and safer to ship, it makes them more robust and trustworthy in general as household objects, and it does not detract from the visual appeal w...

 Almost too simple for a schematic, but here is my wiring diagram.

https://youtu.be/fRX4ST8_PEU   This is Moon Clock 3, the third major iteration of my long-running line of Moon Clocks.  It started as software-only, back in the late 1990s, various forms of a running display of the Moon phase, under Linux.  I was fascinated, when I looked "under the hood" at freeware moon programs, that calculating the phase of the Moon is not a simple matter.  It does not have exactly the same period, every lunar month, and assuming that it does (which is what I tried first!) leads to errors of more than one day in events such as Full Moon.  The correct astronomical formula uses about six different sinusoidal components, and lots of floating-point math: perfect for AVR C! My past hardware Moon Clocks have used discrete LEDs, which were multiplexed and PWM-modulated by the AVR software directly.  In version 3, I am taking advantage of this great new technology which is now cheaply available: programmable RGB LEDs.  adafrui...