editor's blog
Subscribe Now

We Won’t Call You; Just Call Us

One of the challenges with sensors is that, at their most fundamental level, all they do is provide some value reflecting whatever it is they’re sensing. If you want to know that value, you have to go get the value. “You” typically being the main processor in the system.

That’s easy enough if it’s something you occasionally do under the direction of a program, but if you want the sensor to alert you when something happens, then you have to poll constantly so that you know when something changed. That can steal a lot of cycles from the processor, and can be a particular issue for smartphones that have lots of sensors.

I had a discussion about this with Bosch Sensortec’s Leopold Beer at the recent MEMS Executive Congress. He said that with their IMUs, polling still dominates, but that they’ve got a state machine in there that can be programmed to fire an interrupt; their interface supports both polling and interrupts.

For example, the unit has an auto-sleep mode, and can be programmed to wake itself up. You can program in thresholds and timing. You can have it fire an interrupt when changing between portrait and landscape modes; the angles and hysteresis levels are programmable. This relieves the application processor of some of the more mundane polling duties.

For more complex tasks like counting the number of steps you take when running, much more processing is required, so for those tasks the processor still has to go poll the sensor and do the data munging itself.

One solution is to have a separate sensor microcontroller that can manage multiple sensors to offload some of the application processor duties in a programmable way.

A dedicated microcontroller on the same die as the sensor might make sense for so-called “sensor fusion” applications – where the “sensed” state isn’t just the result of a single sensor or even sensor type, but the accumulation of data from numerous sensors synthesized into a single combined more “intelligent” state. It’s certainly possible from a technology standpoint; the only question is whether the cost is justified.

Something to watch for as sensors continue to populate the world…

Leave a Reply

featured blogs
Jul 5, 2022
The 30th edition of SMM , the leading international maritime trade fair, is coming soon. The world of shipbuilders, naval architects, offshore experts and maritime suppliers will be gathering in... ...
Jul 5, 2022
By Editorial Team The post Q&A with Luca Amaru, Logic Synthesis Guru and DAC Under-40 Innovators Honoree appeared first on From Silicon To Software....
Jun 28, 2022
Watching this video caused me to wander off into the weeds looking at a weird and wonderful collection of wheeled implementations....

featured video

Synopsys 112G Ethernet IP Interoperating with Optical Components & Equalizing E-O-E Link

Sponsored by Synopsys

This OFC 2022 demo features the Synopsys 112G Ethernet IP directly equalizing electrical-optical-electrical (E-O-E) channel and supporting retimer-free CEI-112G linear drive for low-power applications.

Learn More

featured paper

3 key considerations for your next-generation HMI design

Sponsored by Texas Instruments

Human-Machine Interface (HMI) designs are evolving. Learn about three key design considerations for next-generation HMI and find out how low-cost edge AI, power-efficient processing and advanced display capabilities are paving the way for new human-machine interfaces that are smart, easily deployable, and interactive.

Click to read more

featured chalk talk

Enabling the Flow of Data in the World of IoT

Sponsored by Mouser Electronics and YAGEO Group

At the heart of our growing IoT ecosystem are high performance semiconductors, but integrated circuits alone cannot make a successful IoT system. In this episode of Chalk Talk, Amelia Dalton chats with Peter Blais from KEMET and Ryan Wenzelman from Pulse about how passive components are crucial to the development of successful IoT frameworks. They take a closer look at RF, wired and power distribution aspects of IoT system development and investigate how YAGEO Group is advancing innovation in the world of IoT with a wide selection of passive components.

Click here for more information about Pulse Electronics World of IoT