BARCELONA — For years at the Mobile World Congress, the smartphone battle has been about the quality of apps processors, basebands, screen sizes and cameras. Hardware matters, because it’s critical for consumers to run apps they want, as they like, on their own phones.
In a new generation of smartphones and wearable devices, however, sensors and sensor hubs are elbowing their way into prominence. The accuracy of MEMS sensors determines the quality of data, and sensor hubs are critical in extracting data to be exploited in different uses.
Bosch Sensortec has come to the Mobile World Congress this week to introduce its first generation of sensor hub products with optimized vital sensing features.
STMicroelectronics unveiled just last week the company’s latest generation of “highly miniaturized” 6-axis MEMS inertial modules with ultra-low-power design.
The two classic MEMS sensor giants, along with other vendors, are facing an inevitable shift from the “old sensor supplier” business model to that of “intelligent sensor” providers, explained Guillaume Girardin, technology & market analyst, MEMS & SENSORS, at Yole Développement.
MEMS vendors are now competing over “how well their sensors can extract data and how much value they can add to this data” for specific uses, Girardin added.
Bosch Sensortec’s new sensor hubs are designed to fuse photoplethysmography (PPG) signals with the onboard inertial MEMS sensors signals for motion compensated heart rate measurement. Stefan Finkbeiner, Bosch Sensortec CEO, told EE Times, “We’ve partnered with Firstbeat, a vital analytics software company, so that they can take our pre-calculated data, add analytics and offer actionable intelligence to users.”
The new sensor hubs, BHV250 and BHV160, integrate three 6-axis inertial MEMS sensors and an accelerometer. BHV160 also includes a gyroscope. These multiple sensors are designed around Bosch Sensortec’s home-grown DSP called ‘Fuser Core,’ which runs Firstbeat’s vital analytics software.
These sensor hubs will “open a world of motion-compensated vital monitoring, activity recognition applications and gesture based user interfaces,” according to the German company.
Meanwhile, ST’s 6-axis MEMS inertial modules – LSM6DSL and LSM6DSM --come with
“Innovative power management, enhanced gyroscope design, and energy-efficient data batching,” according to ST. They cut power consumption by as much as 50% over ST’s current generation devices.
The focus of ST’s ultra-low-power design is in strengthening the smartphone’s “always-on” role.
ST explained that the latest sensors boost “gyroscope accuracy to support an enhanced user experience with Optical Image Stabilization (OIS), visual localization detection, and gesture recognition.” It also improves the accelerometer-driven step detection and step counting and pedometer, ST added.
Is it device or function?
Asked about the competitive landscape of sensor hubs, Bosch Sensortec’s CEO Finkbeiner described a market divided into three groups. At the higher end, ST, for example, is using its microcontroller strength to drive more sophisticated solutions. At the opposite end, Invensense uses a state machine for its hubs, he explained.
Meanwhile, Finkbeiner sees Bosch Sensortec having carved out its own place in between the two. Microcontroller vendors such as ST and Atmel tend to define and build sensor hubs based on their own MCUs. “Our approach is different,” said Finkbeiner. “We go to a MCU company, and tell them the size of memory and power consumption we need for our sensor hubs.”
Depending on use cases, “We adjust the amount of intelligence, software and MCU power required by each application-specific sensor node.”
Yole’s Girardin has a slightly different take.
He explained, “Old sensor suppliers (Bosch, ST) have a deep knowledge of their sensor and can extract the full potential of their component. The difficulty lies in the design of an efficient ASIC and software running with it.”
This approach requires a strong investment in software and chip design to get an efficient solution, he added. “We heard that Bosch Sensortec have strongly increased its software team, focused on sensor fusion and the function delivered by their sensors.”
In contrast, “players like Atmel, NXP (Freescale), Qualcomm and ARM are more microcontroller-oriented, and they have a deep understanding of chip design and software associated with it,” said Yole’s Girardin.
Next page: Where is the bottleneck?