Smartwatch Sensors

8 Smartwatch Sensors – How they work

Smartwatches are acting as fitness trackers coming out with advanced health monitoring and fitness tracking features. All these feature are using multiple sensors in smartphone.

Below are the major sensors used in smartwatches today,

1. Pulse sensor - One of the most common smartwatch sensors is the pulse sensor. Ever wonder why a smartwatch or fitness tracker has a green light that flashes? Smartwatches and fitness trackers test heart rate by measuring blood circulation near your wrist and light it up with LEDs. The colour green was chosen because it is well absorbed by our red blood, allowing optical sensors to accurately gauge blood flow and heartbeat.

2.  GPS (Global Positioning System) - GPS is old technology, but its use in fitness trackers is relatively recent because processors are becoming more powerful. 

The global positioning system comprises a network of 29 satellites in orbit. At any given time, an individual should be within four satellites’ range to determine a precise location.

The GPS receiver receives a low-power, high-frequency radio signal from the satellites. With data from enough satellites, the time it takes for a signal to hit your smartwatch can be converted to your distance from the satellite, which can then be interpreted into precise coordinates. GPS chips are getting great at managing battery consumption, but GPS is still relatively power-hungry compared to other sensors.

GPS, as opposed to basic step counting, enables runners, hikers, and cyclists to quickly chart their workout and assess the environment where they are.