How do smartwatches collect data?

05 Tem 06:20

Smartwatch data collection is really fascinating! For example, heart rate measurement usually relies on *photoplethysmography (PPG)* sensors. These sensors calculate your heart rate by measuring light reflected off your skin. I noticed that after using Garmin’s watch during walks, my sleep-tracked heart rate readings were much more accurate. Step count and movement data, on the other hand, are gathered using an *accelerometer* and *gyroscope*. Thanks to these, your watch doesn’t just count steps—it also analyzes your movement patterns. For sleep data, both movement and heart rate are combined to determine sleep stages (light, deep, REM). Thanks to this, when my watch alerted me that I wasn’t getting enough deep sleep, I started working on improving my sleep quality.