We are surrounded by sensors, and even more are on the way, thanks to smartphones’ popularity and the fast-paced growth of the Internet of Things (IoT).For example, today’s high-end smartphones typically have at least 10 sensors, such as accelerometer, ambient light, proximity and gyroscope sensors.
In India alone, sensors will proliferate at a CAGR of 20 percent through 2020, TechSciResearch predicts. This trend creates opportunities and challenges for companies who need to develop products with multiple sensors in small form factor devices and whose products need to capture information about motion, temperature, pressure, position—and much more. There is no shortage of sensor-based applications, especially in the IoT. Here are a few examples:
Smart energy – For example, presence sensors detect the number of people in a conference room so the heating, ventilation and cooling (HVAC) system always runs at just the right level, instead of wasting energy.
Fitness and healthcare - Wearables such as smart watches not only track a person’s vital signs and movement for fitness applications, but increasingly are used in medical applications and diagnostics.
Automotive – Safety, infotainment and advanced driver assistance systems contain multiple sensors, as today’s cars offer parking assistance, autonomous driving and connectivity to smartphones and other devices.
Security - Facial and eye recognition in PCs and smartphones are replacing login passwords with biometric authentication.
Augmented reality/Virtual reality (AR/VR) - Eye tracking in displays and motion tracking of the head for example,give gamers additional control options.
It’s no surprise that consumer-oriented products alone will need more than $34 billion worth of sensors by 2022, according to Grand View Research. Add in products for the enterprise and government markets, and the opportunity gets even bigger.
Scalable sensor interface
Companies can use sensors to differentiate their products and generate revenue from services that rely upon them, but integrating sensors is challenging work for product developers.
Devices increasingly have multiple, often disparate sensors because a single type can’t provide and capture all the necessary information by itself. For example, a wearable might need to monitor a person’s pulse, skin temperature and even breath in order to provide a holistic picture of his or her health, so the device must be able to aggregate all of that sensor data.
Designers of these devices and applications need an industry-standard way to interface with multiple sensors. That’s why in late 2016, the MIPI Alliance released a sensor interface specification, known as Improved Inter Integrated Circuit (MIPI I3CSM).
When device designers have an industry standard to work with, it reduces their development time, so they can get products to market faster. That’s particularly important for IoT, a market that’s extremely competitive.
MIPI I3C makes it easier to integrate multiple sensors even in small-form-factor devices such as wearables and smartphones. That, in turn, enables the vendors to provide the increasingly svelte devices that consumers crave and that many commercial applications demand, but without tradeoffs in terms of the amount sensors they can accommodate.
MIPI I3C also supports higher-speed data transfers at lower power levels. Those two capabilities are particularly valuable for mobile devices because performance doesn’t come at the expense of battery life.
For example, today’s high-end smartphones typically leverage I2C or SPI to connect sensors, accepting high power for low pin count or low power for high pin count tradeoffs, respectively. However, I3C offers I2C-like low pin count with SPI-like high speed and efficiency, so the data is transmitted much faster and the system can run its calculations and go back to sleep sooner.
MIPI I3C helps achieve scalability and reduce system costs through a variety of techniques. For example, older interfaces lack the ability to initiate a sensor data transfer, so they rely on external general purpose input and output (GPIO) signals to handle those notifications. MIPI I3C has a two-wire interface that reduces or even eliminates the need for external GPIOs. That way, the number of wires in the system does not increase with the increase in the number of sensors.
Authors: Ken Foust, Intel Corp., Chair of the MIPI Alliance Sensor Working Group, and Satwant Singh, Lattice Semiconductor, Vice Chair of the MIPI Alliance Sensor Working Group.