Halo Clock

[scruss]

This is my friend Shae's MicroPython-powered art object, the Halo Clock. It's an actual product. As a clock, there are probably more practical ones out there, but as a glowing delightful art thing it can't be beat.

Although this isn't my project, Shae did share some details with me:

• extremely fast flicker-free LED colour display via SPI
• many themes, including planetary ephemeris, sunrise/sunset, ...
• astronomical calculations done with a custom fixed-point library that uses integers to store more precision that floats
• Responsive to ambient brightness, and can dim down to a tiny projected dot to avoid disturbing light sleepers. Also, light sensor doubles as programming port for setting time and wifi network.

I've had one for a few weeks, and it's lovely.

timelapse of a day in the Sun & Moon theme — https://mastodon.art/@smerp/114982057102364405
https://haloclock.ca/

[peterhinch]

Planetary ephemeris using integers? That is very impressive!

[scruss]

Yes: single precision floats were found wanting. One day we might see some code out of this ...

[peterhinch]

My astronomy library just deals in Sun and Moon calculations but I experienced the same issue. On 32-bit platforms there were significant errors. I had help from Raul Kompaß and Marcus Mendenhall of this parish, who re-jigged the mathematics and fixed the problem.

[DavesCodeMusings]

It's beautiful. It reminds me a bit of black hole images I've seen. I'd love to see it tricked out with a microphone and go into "black hole mode" whenever it detects the song Black Hole Sun by Soundgarden being played.