editor's blog
Subscribe Now

An Orientation Sensor

We now have a new category in the IMU world: Bosch Sensortec has announced the first of what they call Application-Specific Sensor Nodes, or ASSNs. They have dubbed this particular device an Absolute Orientation Sensor. It looks strikingly like an all-in-one sensor hub, with an accelerometer, a gyro, a magnetometer, and a 32-bit ARM-based microcontroller (source not disclosed).

The difference is that a sensor hub per se leaves the software to be executed on the micro pretty wide open for the user to define. The BNO055, by contrast, is really intended to combine the motion sensors via built-in fusion on the micro so that it looks like a higher-level orientation sensor. It essentially bumps up the level of abstraction, burying the sensors and micro inside something more akin to a black box. Data is communicated pre-computed as quaternions rather than raw.

Power is addressed by allowing a stand-by mode where the gyroscope – always the power hog – can be put to sleep. When the accelerometer detects motion, it can then wake the gyro – which responds in a few nanoseconds – so that it can intercept any rotational motion. This assumes, of course, that any rotation missed during that wake-up is negligible. (Quick math sanity check says that if an object rotates, say, 6 degrees in 10 ns, then that’s 60 degrees in 100 ns or a full rotation in 600 ns… divide by 10 to get 60 ns, multiply by a billion to get 60 s, so that would be 100,000,000 RPM… yeah, not even Washington DC can spin anything that fast…)

So full power is around 11 or 12 mA; in motion-wakeable stand-by it goes down to 150 µA. If you put everything to sleep and wake it through I2C instead, you can get down to the 20-µA range.

You can find more on this device in their release

Leave a Reply

featured blogs
Jul 12, 2024
I'm having olfactory flashbacks to the strangely satisfying scents found in machine shops. I love the smell of hot oil in the morning....

featured video

Larsen & Toubro Builds Data Centers with Effective Cooling Using Cadence Reality DC Design

Sponsored by Cadence Design Systems

Larsen & Toubro built the world’s largest FIFA stadium in Qatar, the world’s tallest statue, and one of the world’s most sophisticated cricket stadiums. Their latest business venture? Designing data centers. Since IT equipment in data centers generates a lot of heat, it’s important to have an efficient and effective cooling system. Learn why, Larsen & Toubro use Cadence Reality DC Design Software for simulation and analysis of the cooling system.

Click here for more information about Cadence Multiphysics System Analysis

featured paper

Navigating design challenges: block/chip design-stage verification

Sponsored by Siemens Digital Industries Software

Explore the future of IC design with the Calibre Shift left initiative. In this paper, author David Abercrombie reveals how Siemens is changing the game for block/chip design-stage verification by moving Calibre verification and reliability analysis solutions further left in the design flow, including directly inside your P&R tool cockpit. Discover how you can reduce traditional long-loop verification iterations, saving time, improving accuracy, and dramatically boosting productivity.

Click here to read more

featured chalk talk

Improving Chip to Chip Communication with I3C
Sponsored by Mouser Electronics and Microchip
In this episode of Chalk Talk, Amelia Dalton and Toby Sinkinson from Microchip explore the benefits of I3C. They also examine how I3C helps simplify sensor networks, provides standardization for commonly performed functions, and how you can get started using Microchips I3C modules in your next design.
Feb 19, 2024
19,879 views