Experimental evaluation of the performance of the Nodemcu-BU01 board in ultra-wideband (UWB) distance measurements

Abstract

Ultra-Wideband (UWB) technology has been increasingly recognized as one of the most accurate solutions for indoor localization systems, particularly in applications that require high spatial resolution, robustness to interference, and low power consumption. Despite this growing interest, the NodeMCU-BU01 board remains poorly explored in the literature, and its performance under real experimental conditions is still insufficiently documented. In this context, this work presents a comprehensive experimental investigation of the distance measurement and positioning capabilities of the NodeMCU-BU01 using the Two-Way Ranging (TWR) method. Measurement campaigns were conducted over distances ranging from 5 m to 50 m, considering different angular configurations between anchors and tags, module orientations, numbers of transmitted packets, and multi-anchor setups. The collected data were analyzed using statistical metrics such as mean, standard deviation, mean absolute error (MAE), and interquartile range, as well as normality tests, allowing a detailed assessment of measurement stability and reliability. The results demonstrate that the BU01 achieves distance errors below 17 cm under line-of-sight (LOS) conditions, exhibiting performance comparable to that of widely used DW1000 transceivers. Furthermore, position estimates obtained through trilateration with three anchors presented errors ranging from 0.32 m to 0.42 m, which are consistent with expectations for low-cost UWB systems. Overall, this study contributes to the experimental characterization of the NodeMCU-BU01 and provides relevant technical insights for its adoption in indoor localization systems.