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Show HN: ESPectre – Motion detection based on Wi-Fi spectre analysis

(github.com)
215 points francescopace | 1 comments | 17 Nov 25 14:40 UTC | HN request time: 0s | source

Hi everyone, I'm the author of ESPectre.

This is an open-source (GPLv3) project that uses Wi-Fi signal analysis to detect motion using CSI data, and it has already garnered almost 2,000 stars in two weeks.

Key technical details:

- The system does NOT use Machine Learning, it relies purely on Math. — Runs in real-time on a super affordable chip like the ESP32. - It integrates seamlessly with Home Assistant via MQTT.

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francescopace ◴[17 Nov 25 22:31 UTC] No.45959155[source]▶
Fun fact: I’m working on turning ESPectre into a Wi‑Fi Theremin (the musical instrument you play by moving your hands near an antenna).

The idea of “playing” by simply moving around a room sounds a bit ridiculous… but also kind of fun.

The key is the Moving Variance of the spatial turbulence: this value is continuous and stable, making it perfect for mapping directly to pitch/frequency, just like the original Theremin. Other features can be mapped to volume and timbre.

It’s pure signal processing, running entirely on the ESP32. Has anyone here experimented with audio synthesis or sonification using real-time signal processing?

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cweagans ◴[18 Nov 25 00:25 UTC] No.45960041[source]▶
I wonder if somebody could make an open hardware version of the Leap Motion with this technique (though I'm not sure how accurate/repeatable the sensing is - Leap Motion could detect with an accuracy of < 0.7mm)
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1. francescopace ◴[18 Nov 25 10:49 UTC] No.45963523[source]▶
That's a great thought. The challenge is that Wi-Fi sensing (CSI) is measuring multipath changes across a few meters, not direct motion in a small volume like Leap Motion. I think its accuracy is measured in centimeters, not sub-millimeters.