Sensor Fusion and New Sensor Interface Developments Open Up Innovation

Last week at the MEMS Executive Congress in Scottsdale, Arizona (Nov. 5-7, 2014) two separate announcements were made that will have long term impact on sensors. The MEMS Industry Group announced the first open source algorithm community for sensor fusion and the MIPI Alliance introduced a new sensor interface specification.

MIPI I3C

The I2C, also known as I Squared C, standard has been used extensively for sensor interface.  Many sensor hub controllers, mostly microcontrollers, use I2C for connecting to sensors.  But I2C has its limitations in terms of power, speed and scalability. SPI is another interface standard that is used for sensors, but this requires more pins. 

MIPI is addressing the interface fragmentation and scalability issues with a new sensor interface specification, MIPI I3C. As that name implies it is backward compatible with I2C. But the new standard provides data throughput capabilities comparable to SPI. According to MIPI “the name MIPI SenseWire℠ will be used to describe the application of I3C℠ in mobile devices and the use of the I3C interface for mobile devices connecting to a set of sensors, directly or indirectly.”

This new standard has been developed because of the steadily growing proliferation of sensors in smartphones. A new standard was needed that could be scalable. MIPI has developed I3C with the participation of sensor vendors and other companies in the mobile ecosystem.

The I3C specification is scheduled for Working Group completion by the end of 2014.  Ratification and approval is expected in 1Q 2015. Speaking with MIPI it is possible that I3C could be implemented in devices by the end of 2015.

MIG AIC

The Accelerated Innovation Community (AIC) is the first open source algorithm cooperative for sensor fusion applications. The inaugural AIC member is Freescale which has provided support and innovation to AIC.  

AIC’s goal is to accelerate sensor algorithm development. It enables collaborative sensor data collection. The intent is to foster open innovation to spur sensor applications.

For many semiconductor companies, software is not their main strength.  AIC will enable smaller players to move up the value chain.  Larger players will be able to offload and share R&D costs. An open source community will encourage others to develop different use cases and ecosystems. This will lead to greater diversification, lower cost for software development, and shorten the R&D cycle.

To kick off AIC Freescale is offering its Open Source Sensor Fusion Library which includes C source library for 3-, 6-, and 9- axis Sensor Fusion. There is also a Sensor Fusion Starter Kit that includes a Kinetis based (ARM MCU) development board. Freescale also offers customization services through its software services.

Other companies have quickly added support to AIC. Coming on board are Analog Devices, Berkley Sensor & Actuator Center, Carnegie Mellon Univeristy, Kionix and NIST. PNI Sensor Corp. will contribute three algorithms: quaternion to heading pitch and roll; heart rate monitoring using PPG sensor; and step counting.  Other MIG member companies are expected to join and provide further support over the next couple of months.

Semico Spin

The MIPI I3C standard and MIG AIC are completely separate developments that have no connection to each other. It is coincidental that they have been announced at the same time. Semico sees this as a serendipitous event. The two complement each other very well.  MIPI I3C addresses the hardware side of Sensor Fusion and MIG AIC addresses the software side.

MIPI I3C offers a new topology that will enable more sensors to be designed in.  While MIPI focuses on the smartphone and tablet markets, the technology is being leveraged into other applications. The standards are enabling other designs by expanding the capabilities of the ecosystem.

MIPI I3C will enable more flexible designs. Sensor data can be shared between an applications processor and a sensor hub controller. More than one sensor hub controller may be designed in sharing sensor data. Sensor Fusion algorithms can be partitioned among the application processor and sensor hub controllers for different applications. This will open up innovation for new applications.

MIG AIC will enable companies to address new applications which will utilize new designs developed around MIPI I3C. There will be more sensors, specialized algorithms which will become more complex.  Many system designers are not familiar with sensors and sensor fusion. MIG AIC will provide tools and software they will need to proliferate sensors into new markets.

A few months ago there were several mergers and acquisitions impacting sensor fusion. In May 2014, Fairchild announced the acquisition of Xsens, the Dutch company known for motion tracking software. On June 24, 2014 Audience announced it would acquire Sensor Platforms. On July 7, 2014 InvenSense announced it was acquiring two companies, Movea and Trusted Positioning, Inc. Thus, the only remaining independent third party sensor fusion developer without a competing chip is Hillcrest Labs.

There was concern at the time that these developments might stifle sensor fusion development. Chip companies wanted to integrate more IP in their respective technologies. The recent announcement of MIG AIC opens up sensor fusion to many more developers. Semico believes that along with MIPI I3C, there will be accelerated development for sensor fusion across new markets.