ESPectre Sensor: open-source motion detection system for ESP32 (opens in new tab)

(espectre.dev)

5 points882542F3884314B4mo ago2 comments

2 comments

This is a clever approach to motion detection! Using Wi-Fi spectrum analysis is much more elegant than traditional PIR sensors or cameras for privacy-conscious setups.

The ESP32 is perfect for this - cheap, low power, and has the right hardware. I'm curious about the accuracy compared to traditional sensors. How well does it handle multiple people moving simultaneously? And what's the typical detection latency?

The Home Assistant integration is a nice touch. This could be really useful for automation triggers without needing line-of-sight or dealing with camera privacy concerns.

francescopace4mo ago

Author here. Thanks for the interest!

Multiple people moving: The system detects "motion presence" rather than counting individuals. With multiple people, CSI variance increases, so detection works well. Distinguishing how many people would require ML (on the roadmap).

Detection latency: The algorithm processes each packet in real-time (~10ms @ 100 pkt/s), so detection is essentially instant. The default Home Assistant publish rate is 1 second to avoid flooding the event bus, but it's fully configurable via publish_interval.

Accuracy vs traditional sensors: See PERFORMANCE.md in the repo for detailed benchmarks.

Main advantages over PIR: no line-of-sight needed (Wi-Fi passes through walls) and no dead zones.

Happy to answer more questions!

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