The work addresses the design and implementation of a miniature, energy-efficient multi-sensor platform for indoor asset tracking in warehouse and production environments. The proposed system localizes objects using time-based distance measurement methods, namely Two Way Ranging (TWR) and Time of Flight (ToF) markers obtained from ultra-wideband (UWB) transmissions. Custom four-layer PCB tags and anchors populated predominantly with 0201 components enable compact integration of the UWB transceiver, Bluetooth interface and an environmental sensing module (temperature, humidity and pressure), while Power over Ethernet (PoE) support on the anchor side simplifies deployment in industrial facilities. Motion-triggered activation based on an on-board accelerometer allows distance measurements to be initiated only when significant movement occurs, which reduces energy consumption and limits data acquisition to events relevant for logistics processes. A calibration and test campaign carried out in a 28 m indoor corridor demonstrates that, after antenna-path correction, raw ToF-based distance estimates typically remain within 10–20 cm of the ground truth for most control points, with larger deviations attributable to multipath propagation. To further stabilize the readings, a one-dimensional Kalman filter is applied to distance time series, reducing the mean RMS error from 81.19 cm to 25.63 cm (68.4% reduction) and improving the signal-to-noise ratio by approximately 10 dB. The results confirm that the proposed hardware–software architecture can provide accurate, energy-aware UWB localization suitable for integration with warehouse management and production control systems.