The device uses an Arduino Nano, a Neopixel ring ... [Mark] had won the LED ring in a competition so the total cost of this — to him — was low, but it wouldn’t be too much even if you ...

[rhoalt] had neither, but he did have several 8 LED Neopixel rings lying around ... The rest of the build is pretty plain vanilla — an Arduino Nano clone, a DS3231 RTC, a Lithium battery ...