Meet the Sensors

I often write about the Internet of Things, or the soon-to-be-cliché IoT. You know, the smart-fridges, smart-cars, smart-thermostats, healthcare devices, wearables and any of those connected devices that have a sensor, gathers data and reports back to some entity. You are able to control these devices (and see the data) with mobile apps or even your own voice and gestures. They are all the rage and sitting at the top of the Gartner Hype Cycle.

But it’s all the various sensors inside those devices that are doing the actual measuring, calculating, tracking and reporting. Each has its own specialty providing specific functionality. I’ve always wondered about what’s inside some of the wearables let’s take a look at a few.

Have you ever wondered what spins the screen so you’re not looking at an upside down picture? That’s an Accelerometer. It measures orientation and movement. The iPhone was the first to use this back in 2007 and amazement ensued. It can tell the difference between running away from a charging buffalo in Yellowstone verses making faces with a chimp at the zoo. It can also tell if you’re sleeping simply by the fact that you haven’t moved for a while. These are typically used to track step count and how well you’ve rested.

I noted that the accelerometer measures step count but what about those steps up a flight of stairs? Well, that would be the Altimeter. Altimeters measure altitude so it can sense changes in height. In conjunction with the steps the accelerometer counted, the altimeter will add its bits and give you a more accurate calorie count for those fire escape runs. Instead of asking how tall someone is, next time ask ‘What’s your alti?’

And if you’re going to step out for a run, you might want to know if it’ll be sunny or sprinkles during the trek. Often seen as a smaller dial on an outdoor clock but now on wristbands, a Barometer measures atmospheric pressure – the weight of air in the Earth’s atmosphere. It’s used in forecasting the weather and you often hear meteorologists note, ‘There’s a high ridge of atmospheric pressure keeping the rain away.’ At least that’s what they’ve been saying in California about the drought.

So you thought of attempting an Iron Man competition but wondered if your device could differentiate between the swimming, biking and running. You’re in luck if your device has a Gyroscope. Using the Earth’s gravity, it can help determine orientation. The big difference between an accelerometer and a gyroscope is that a gyroscope can also measure rotation or more specifically, the rate of rotation around a particular axis. Gyroscopes take into account the Earth’s gravity and rotation while the accelerometer does not.

If tracking stars for navigation and location like the early Polynesians is not your style, then the ever popular GPS is your tool. Using three satellites to ‘triangulate’ your location, the receiver measures distance to the first satellite. Based on that, you are in a certain sphere location on the planet. It then measures the distance to the second satellite to get another sphere location. Therefore, you must be somewhere on the circle where these two spheres intersect. By using a third satellite reading, the sphere that cuts through the circle of the intersection of the first two spheres narrows your location even more. Now our position is narrowed to two points in space. One of those two points is so absurd and instantly tossed, thus leaving you with an exact location.

There are a bunch of other sensors like Optical Heart Rate Monitors, typically worn on the wrist and it shines a tiny light against your skin to measure the blood pumping through your arm veins. And the various Gesture Tech things that use a little camera to see your hand and body movements to translate that into action on a gaming device, or a drone following your Snake River Canyon jump or even turning up the volume on the TV. It’d be cool to move something out of the way by effortlessly swiping your hand in the air, huh?

Sensors have been all around us for a while but now they are becoming close confidants. We should get to know our new Ohana.