SDG #197 A WS2812 NTP Wharton Style LED Clock powered by ESP32

This build takes inspiration from the classic Wharton style ring clock and reworks it around modern, cheap parts: a ring of WS2812B addressable LEDs driven by an ESP32, with time pulled over WiFi from an NTP server so there is no RTC, no crystal trimming and no drift to worry about.

The interesting engineering detail here is not the software but the board itself. A ring of individually addressable RGB LEDs looks trivial on paper, yet the routing, the LED spacing and the daisy chained data line all matter if you want an even, readable display rather than a blotchy circle. The video walks through the PCB layout choices, then looks at what each LED actually puts out spectrally, which is a useful reality check: the red, green and blue dice in a WS2812B are not perfectly balanced, so apparent brightness and colour mixing at low duty cycles can be uneven. That directly affects how legible the hour, minute and second markers are.

Power is the other practical constraint. Dozens of WS2812Bs at full white will happily pull more current than a small USB supply can deliver, so the testing covers supply selection and what happens when the rail sags. Anyone repeating the project should size their PSU for worst case rather than typical brightness.

Assembly economics are covered too, comparing hand soldering against paying for machine assembly on a board with this many identical placements, plus programming the ESP32 using a separate FTDI breakout instead of adding a USB to serial chip to every board. That is a sensible cost saving trick for any small run ESP32 project.