# PPG

Status: archived
- post: /posts/ppg/
- repo: https://github.com/afonsocraposo/ppg



Put a finger over the camera and flash, and the app reads the tiny changes in light as your blood pulses: a photoplethysmogram (PPG). From that it gets your heart rate, no wearable needed.

It grew out of my biomedical engineering research. The [write-up](/posts/ppg/) explains how it works and how to build one.