Inside the printed puck is an Arduino Nano running an MPU6050 accelerometer, a 12-NeoPixel ring, and a piezo buzzer. [DIY_Maxell] reused a power bank charging circuit to charge up the small LiPo ...

The article says he had “a” neopixel ring lying around. Not sure where the HaD writer got several. Also, these rings are $2.70 per pair on Aliexpress, meaning 8 could be as little as $10.80 ...

Adafruit has this week added a new addition to their range of electronic components, announcing the availability of the new Particle/Spark NeoPixel Ring Kit, that is now available to purchase ...

Based on Arduino Pro Mini card with ATmega328P microcontroller, the 3 axis motion sensor gyroscope allows you to track the movement of the head or arm and replicate it to servos.