Low power smart sensor wireless platform for IoT devices

Paul Boughton

Dialog Semiconductor and Bosch Sensortec are to create an extremely low power smart sensor platform that combines Bosch Sensortec’s sensors with Dialog’s Bluetooth Smart technology.

The product resulting from the collaboration is the world’s lowest power 12-DOF smart sensor reference platform for gesture recognition in wearable computing devices and immersive gaming, including augmented reality, and 3D indoor mapping and navigation.

The platform combines Dialog’s DA14580 Bluetooth Smart System-on-Chip (SoC) with three low power sensors from Bosch Sensortec: the BMM150 for 3-axis geo-magnetic field measurement, the BME280 pressure, humidity and temperature sensor, and the 6-axis BMI160 (a combination of a 3-axis accelerometer and 3-axis gyroscope in one chip). The resulting unit, built onto a 14 x 14mm2 printed circuit board, consumes less than 500µA from a 3V coin cell when updating and transferring all 12 x 16 bits of data wirelessly to a smartphone.

The DA14580 SmartBond SoC, which has already been adopted by numerous leading manufacturers of wearables, integrates a Bluetooth Smart radio with an ARM Cortex-M0 application processor and intelligent power management. It more than doubles the battery life of an application-enabled smartphone accessory, wearable device or computer peripheral in comparison with competing solutions.

The DA14580 includes a variety of analogue and digital interfaces and features less than 15 mW power consumption in active mode and 600 nA standby current. It is half the size of rivals, measuring 2.5 x 2.5 x 0.5mm.

Bosch Sensortec’s BMI160 6-axis Inertial Measurement Unit (IMU) integrates a 16 bit, 3-axis, low-g accelerometer and an ultra-low power 3-axis gyroscope within a single package. When the accelerometer and gyroscope are in full operation mode, the typical current consumption is 950 µA, only half of that of its nearest rivals.

The BMM150 integrates a compact 3-axis geo-magnetic field sensor using Bosch Sensortec’s high performance FlipCore technology.

The BME280 Integrated Environmental Unit combines sensors for barometric pressure, humidity and temperature measurement within a single package. The precise altitude measurement function of the BME280 is a key requirement in applications such as indoor navigation with floor tracking. Additionally, the BME280 has best-in-class response time for humidity determination of one second only, accurate ambient temperature measurement and very low current consumption.