It took two years and over $100 for Matt Inglot to build his DIY dog collar light, most of which was spent learning to design custom PCBs. While it may have been time-consuming, the end result looks great and features an ATtiny84 microcontroller, a pair of RGB LEDs, an on/off pushbutton and a 3D-printed water-resistant enclosure. It’s also equipped with a pair of CR2032 batteries to power the collar, which lasts for around 40 hours before needing a replacement.
Check out Inglot's video below to see a complete overview of the dog collar project.
Not quite the cyberpunk dog I want, but it's a step closer.