Counting your steps is a big deal if you want to keep tabs on your physical activity levels.
And you can either use a fitness tracker or pedometer to achieve this goal. However, many people using either of these devices do not really understand the technology behind it.
So the question we are answering here is how does it work?
How Fitness Trackers Calculate Steps Taken
Generally, fitness trackers calculate steps by measuring motion. And in this post, we will talk a look at the technology behind this process has evolved over the years.
The early fitness trackers (mainly pedometers) were entirely mechanical and they worked a bit like pendulum clocks (the ones with a swinging bar powered by a slowly falling weight).
Basically when you walk, your body tilts to one side and you swing a leg forward. Then your body tilts the other way and you swing the other leg forward too. Each tilt of the hips and shift of the legs is a step.
Assuming each step is pretty much the same length; all we need to do is count the number of steps we make in a day, by counting the number of times our body tilts from side to side. We can then multiply the number of steps by the length of each one to figure out the overall distance walked. This was how the pedometer worked initially.
Over the years, the manual pedometer evolved in to the electronic device. In this case, a metal pendulum is wired into an electronic counting circuit by a thin spring. Normally the circuit is open and no electric current flows through it. As you take a step, the hammer swings across and touches a metal contact in the center, completing the circuit and allowing current to flow.
The flow of current energizes the circuit and adds one to your step count. As you complete the step, the hammer swings back again (helped by the spring) and the circuit is broken, effectively resetting the pedometer ready for the next step. The pedometer shows a count of your steps on an LCD display; most will convert the step count to an approximate distance in miles or kilometers (or the number of calories you’ve burned off) at the push of a button.
In recent time, more sophisticated pedometers work entirely electronically and, since they have no moving parts, they tend to be longer-lasting, more reliable, and considerably more accurate.
In this case, instead of the swinging pendulum-hammer, they measure your steps with two or three accelerometers. These are microchips arranged at right angles that detect minute changes in force as you move your legs.
The most recent technology uses a 3-axis accelerometer which tracks movement in every direction. Also, some come with a gyroscope too to measure orientation and rotation.
Also, if you’re going up or down a mountain or a series of steps, there are trackers that come with an altimeter to measure your altitude, handy for working out the height of the mountains you’ve climbed or the number of flights of stairs you’ve managed to get up and down during the day.
Overall, the sensors embedded in a fitness tracker measures the acceleration, frequency, duration, intensity and patterns of your movement. All of these taken together provides with data points that can help the tracker know if you’re walking down the road or just waving at someone you know.