Digital precision studio/broadcast master clock with WiFi configuration, NTP client/server and GPS time sync.
You'll find a complete project description on my personal home page.
The enclosure is an 25x25 cm IKEA "Sannahed" photo frame, which is deep enough to encapsulate the circuitry. I replaced the provided plexi glass with a dark acrylic glass plate.
There are no traditional buttons to control the clock. Instead, it has a browser based web configurator. When powered on, the clock will expose a dedicated wifi network for 30 seconds. Connect to the network in order to access the clock's control panel.
The clock supports time synchronization over the web (NTP) or via a range of GNSS satellite systems (GPS/QZSS, GLONASS, BeiDou, Galileo). It acts as a highly accurate NTP time server for other clocks on your LAN.
LED brightness is auto-adjusted to ambient light conditions. This feature can be overridden in the control panel.
It also has a stopwatch and a countdown timer that is operated from the browser interface.