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. 2025 Oct 21;25(20):6499.
doi: 10.3390/s25206499.

BLE-Based Custom Devices for Indoor Positioning in Ambient Assisted Living Systems: Design and Prototyping

David Díaz-Jiménez  1 , José L López Ruiz  1 , Juan Carlos Cuevas-Martínez  2 , Joaquín Torres-Sospedra  3 , Enrique A Navarro  3 , Macarena Espinilla Estévez  1
Affiliations

BLE-Based Custom Devices for Indoor Positioning in Ambient Assisted Living Systems: Design and Prototyping

David Díaz-Jiménez et al. Sensors (Basel). .

Abstract

This work presents the design and prototyping of two reconfigurable BLE-based devices developed to overcome the limitations of commercial platforms in terms of configurability, data transparency, and energy efficiency. The first is a wearable smart wristband integrating inertial and biometric sensors, while the second is a configurable beacon (ASIA Beacon) able to dynamically adjust key transmission parameters such as channel selection and power level. Both devices were engineered with energy-aware components, OTA update support, and flexible 3D-printed enclosures optimized for residential environments. The firmware, developed under Zephyr RTOS, exposes data through standardized interfaces (GATT, MQTT), facilitating their integration into IoT architectures and research-oriented testbeds. Initial experiments carried out in an anechoic chamber demonstrated improved RSSI stability, extended autonomy (up to 4 months for beacons and 3 weeks for the wristband), and reliable real-time data exchange. These results highlight the feasibility and potential of the proposed devices for future deployment in ambient assisted living environments, while the focus of this work remains on the hardware and software development process and its validation.

Keywords: GATT; Zephyr RTOS; bluetooth low energy; fog computing; indoor localization; reconfigurable systems; wearable devices.

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Conflict of interest statement

The authors declare no conflicts of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.

Figures

Figure 1
Figure 1
Main PCB and flexible PCB.
Figure 2
Figure 2
Wristband housing.
Figure 3
Figure 3
Mechanical design and dimensions of the wristband.
Figure 4
Figure 4
Beacon PCB.
Figure 5
Figure 5
Beacon housing.
Figure 6
Figure 6
Mechanical layout of the beacon unit.
Figure 7
Figure 7
System architecture based on ASIA Beacon and wristband.
Figure 8
Figure 8
Beacon in anechoic chamber.
Figure 9
Figure 9
Histogram and Boxplot of RSSI distribution.
See this image and copyright information in PMC

References

    1. Obeidat H., Shuaieb W., Obeidat O., Abd-Alhameed R. A review of indoor localization techniques and wireless technologies. Wirel. Pers. Commun. 2021;119:289–327. doi: 10.1007/s11277-021-08209-5. - DOI
    1. Leitch S.G., Ahmed Q.Z., Abbas W.B., Hafeez M., Laziridis P.I., Sureephong P., Alade T. On indoor localization using wifi, ble, uwb, and imu technologies. Sensors. 2023;23:8598. doi: 10.3390/s23208598. - DOI - PMC - PubMed
    1. Kolakowski J., Djaja-Josko V., Kolakowski M., Broczek K. UWB/BLE tracking system for elderly people monitoring. Sensors. 2020;20:1574. doi: 10.3390/s20061574. - DOI - PMC - PubMed
    1. Botler L., Spörk M., Diwold K., Römer K. Direction finding with uwb and ble: A comparative study; Proceedings of the 2020 IEEE 17th International Conference on Mobile Ad Hoc and Sensor Systems (MASS); Delhi, India. 10–13 December 2020; pp. 44–52.
    1. Dinh T.M.T., Duong N.S., Nguyen Q.T. Developing a novel real-time indoor positioning system based on BLE beacons and smartphone sensors. IEEE Sens. J. 2021;21:23055–23068. doi: 10.1109/JSEN.2021.3106019. - DOI

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