Tag Archives: TOF

Is Chirp Microsystems Usurping UI?

User Interface (UI) is on the verge of a major shakeup as it was evident at the Mobile World Congress (MWC) this year. Leaving behind other UI interfaces such as motion, touch, and voice, touch-less is now looming large and lucrative as the new UI of choice for consumer devices. Touch-less means you can operate your device simply by waving your hands near it, without actually touching it.

The CEO of Chirp Microsystems, Michelle Kiang is of the opinion that the UI revolution has been bringing on constant consumer electronics breakthroughs. Chirp is offering a single-chip sensor working as a time-of-flight (ToF) ultrasonic unit, to allow users to interact with wearable devices even without actually touching their screens, or interacting with devices that work without screens.

Although the touch-less technology, based on ultrasonic sensing, is not yet ready to replace other existing UIs, Kiang is of the view that it will certainly add another level of modality to automotive, smartphones, AR/VR, and wearables.

Chirp Microsystems is a startup from Berkeley, California, with a UC Berkeley and Davis heritage. At the MWC, they presented the company’s first high-accuracy ultrasonic sensing development platform. As they have especially targeted the platform for wearables, it has ultra-low power consumption. The breakthrough by the team of engineers and researchers at the University of Berkeley and Davis—miniaturization of the MEMS-based ultrasonic sensor—formed the foundation of the startup.

According to Kiang, most smartwatches and other wearables suffer from small screen sizes that have limited surface, and do not work well with fat fingers. The MEMS-based ToF ultrasonic sensors embedded inside the smartwatch helps users with any type of fingers to use gestures. They can control the functions of the watch, even without touching the screen.

For instance, the wearable wristband has no space for a screen on it. That makes it powerless to interface with its wearer directly. However, the ToF ultrasonic sensor is tiny enough to be embedded within the band or even in a ring. Now, all popular wearable bands can interact with their wearers.

The ToF ultrasonic sensor from Chirp comes in a 3.5 mm package called Land Grid Array (LGA). According to the company, the chip operates on a 1.8 V supply, and is similar to a MEMS based microphone. Integration into consumer electronics products is simple, as the IC has an I2C interface.

Along with the MEMS ultrasound transducer, Chirp has also developed an accompanying mixed-signal CMOS ASIC. Then they combined both into a system-in-package, making it easier to use.

The on-board microprocessor with the ToF sensor works in an always-on mode for applications requiring wake-up sensing. According to the company, the pulse-echo sensing range is greater than a meter, but consumes only 9 µA, working at 1 Hz sampling rate.

After the transfer of the IP and the key researchers from the University to Chirp, including David Horsley, several PhD students and postdocs from the University have also joined Chirp. David Horsley was a professor at the University of California and Davis, in the department of mechanical and aerospace engineering, and is now the CIO at Chirp Microsystems.

Moving 3-D Sensing Into Smartphones and Vehicles

Chirp Microsystems, a new startup from Berkeley, California, has developed a new Time of Flight (ToF) ultrasonic sensing platform for use in wearables and Virtual and Augmented Reality (VR/AR) systems. They have selected some big customers to whom they have made available their development platform.

At present, the high-end VR/AR systems are typically confined to a prescribed space, or tethered to a base station. The limit comes from the requirements of additional equipment in the space for creating better tracking experience. Usually, the additional equipment is often a magnetic sensor or a camera-based system that can correct drifting by using the inertial measurement unit (IMU) within the head units of the VR/AR system.

Chirp has demonstrated they can embed their miniaturized MEMS ultrasound sensors within the AR/VR head unit. With the sensors in place, the user has a 360-degree immersive experience, as the tracking system moves along with the user. Supporting inside-out tracking, the ultrasound sensors from Chirp can have controllers or input devices working with six-degrees of freedom—offering 3-D sensing.

VR/AR systems already use the optical or camera-based system for tracking. However, the camera is only a 2-D device, incapable of providing any sort of depth information. Even to detect if objects have shifted from one frame to another, a camera needs to use the point cloud, while applying very complicated calculations.

On the other hand, ToF ultrasound sensors can easily detect 3-D movement. This is because the technology is adept at triangulating data easily, and simpler calculations demand much less power.

Although it is another option for 3-D sensing, infrared technology has limited use when the sensor is outdoors—the heat outdoors tends to wash out infrared sensing. However, ultrasound sensors are robust and consume low power, and able to perform well in VR/AR systems outdoors, even in the presence of a bright sun.

While using the ToF ultrasound sensors in VR/AR systems, Chirp hopes the low-end VR/AR systems will improve the interactive experience, and smartphones and vehicles can start using the untethered high-end VR/AR systems.

For instance, smartphones use infrared technology currently as a proximity sensor. This actually prevents the user’s cheek from dialing the phone by itself. However, this requires the smartphone to have a tiny hole for the infrared sensor embedded on the face of the smartphone.

According to Chirp, some smartphone vendors have shown interest in replacing infrared with ultrasound. This would improve the aesthetics of the smartphone by removing the tiny hole on the face of the phone. Additionally, the ultrasound sensors can also add features such as autofocus when taking selfies, and add simple gesture functions to the phone.

At present, vehicles use bulky ultrasound sensors, for say, backing up. Chirp hopes to replace them with its ToF ultrasound sensors. They can also use the sensors as a User Interface (UI) inside cars for infotainment systems. However, as automotive applications tend to use long design-in cycles, Chirp is keeping this in low-priority for the time being. Chirp is planning to ramp up production of its ultrasound MEMS sensors and accompanying ASICS later this year.