Table 1.

Tracker device parameters.

Tracking sensor Communication protocol RSSI Receiver sensitivity	Laird BL654 Proprietary 2.4 GHz 1 dB resolution −95 dBm (1 Mbps)
Microcontroller	Nordic nRF52840 64 MHz Cortex-M4 with FPU 1 MB Flash, 256 KB RAM 2.4 GHz Transceiver
Real-time clock Accuracy	Micro Crystal RV-8263-C7 RTC ±20 ppm @ 25 °C
Temperature sensor Range/Accuracy Resolution Body contact	Silicon Labs SI7051-A20-IM 35.8–41 °C/±0.1 °C 20–70 °C/±0.13 °C 14-bit Surgical steel
Barometer Range Precision/Absolute accuracy	Infineon Technologies DPS310 300–1200 hPa ±0.002 hPa/±1 hPa
Internal memory Format Size Clock	Macronix MX25R1635FZUILO Flash 16 Mb 33 MHz
Dimensions (case)	Ø 46 × 13 mm
Weight	30 g (strap included)
Power supply Battery life Charging	3.7 V Li-Pol 300 mAh Approx. 80 days 60 min via a micro-USB connector
Next features	RGB LED signalization Switch on/off by unplugging/plugging to the charger Service button