You can buy all kinds of conventional clocks that have hands and numbers for easy reading. Or, like [Fabio Ricci], you could build yourself something a little more esoteric, like this neat shadow ...

This project implements a Real-Time Location System (RTLS) using Ultra-Wideband (UWB) technology to achieve sub-10cm positioning accuracy indoors. Unlike GPS, Wi-Fi, or Bluetooth-based solutions that ...