German firm Bosch Sensortec has introduced a barometric pressure sensor that couples low power consumption with accuracy to provide altitude tracking in wearables, hearables or IoT devices.

The BMP581 is suitable for applications such as fitness tracking, fall detection, indoor localisation and navigation.

“Building on the excellent performance and low power consumption of previous generations of Bosch sensors, our new BMP581 now delivers an entirely new level of accuracy,” said Stefan Finkbeiner, CEO at Bosch Sensortec. “It’s breathtakingly accurate: it can measure a barometric pressure fluctuation that’s equivalent to one-thousandth of the weight of a mosquito (7.6μg).”

This level of accuracy lets the sensor detect an altitude change of a few centimetres. It can therefore monitor movement in fitness applications down to the level of individual pull-ups or push-ups, and can provide highly accurate location information for indoor localisation, navigation and floor detection to provide key data for emergency call requirements (E-911).

The sensor can improve flight stability and landing accuracy in drones, and help detect water levels in household appliances to avoid flooding.

Relative accuracy is ±0.06hPa and typical absolute accuracy is ±0.3hPa. Full accuracy is available over a measurement range from 300 to 1100hPa. Typical temperature coefficient offset (TCO) is ±0.5Pa/K and RMS noise 0.08Pa at 1000hPa, typical. Long-term drift over 12 months is ±0.1hPa.

Compared with the BMP390, the previous generation of Bosch barometric pressure sensors, the BMP581 draws 85% less current, noise is 80% lower and TCO is reduced by 33%.

Typical current consumption is 1.3μA at 1Hz to extend battery life, while the deep standby mode draws 0.5μA. The sensor has an I²C, I³C and SPI (three and four-wire) digital, serial interface.

The device comes in a ten-pin LGA package shielded by a metal cover, measuring 2.0 by 2.0 by 0.75mm.