I've been working on this project for a while. Two posts about it: One, describing the clock I built for the restaurant my daughter owns.

https://medium.com/@maolson/the-uqbar-clock-240c929fdc1d

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The UQBAR Clock!

I built a clock for UQBAR, my favorite café in Berkeley, California. Full disclosure: My daughter and son-in-law, Jennie and Benji Smith…

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Building the UQBAR Clock

Last year, the owners of UQBAR Café in West Berkeley invited me to build a metric clock for their restaurant. I’ve been preoccupied with…

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@mikeolson very cool! Alan’s kid wants to know what color it turns for primes

@jackowayed Configurable -- you can change the display RGB colors for ordinary and prime numbers with the companion iPhone app, via Bluetooth.

Currently it's a red, shaded somewhat to pink.