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

(github.com)
215 points francescopace | 3 comments | 17 Nov 25 14:40 UTC | HN request time: 0.001s | 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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1. reconnecting ◴[17 Nov 25 23:00 UTC] No.45959427[source]▶
I'm sure the kids will love this! Wi-Fi Theremin sounds great.
replies(1): >>45959925 #
2. francescopace ◴[18 Nov 25 00:06 UTC] No.45959925[source]▶
You hit the nail on the head! That's precisely the motivation.

Having two kids myself, I've thought of turning it into a game: blindfolded hide-and-seek where the pitch of the Wi-Fi Theremin tells the seeker how close they are to the 'signal disruption' of the other person. It's essentially a real-time sonar game!

replies(1): >>45966834 #
3. reconnecting ◴[18 Nov 25 14:45 UTC] No.45966834[source]▶
Exactly! That is kind of fun that I had in mind.