Fun engineering/privacy problem: design a device that plugs into an ESP32 based sensor node that has a microphone and reports ambient noise levels in dBa via MQTT or similar.
That's the easy part.
The hard part is to do so in a way that you can prove it's incapable of being used as a bug/listening device even in the worst case scenario (attacker running arbitrary code on any programmable component).
My initial thought is to record audio from a MEMS mic into a tiny MCU with limited RAM capacity, then report results to the main system processor through some kind of R-C low pass filter that only lets like one bit per second pass through.
Or maybe a bank of analog filters and peak hold blocks? I want proper weighted dBa.
Andrew Zonenberg
npub1cd…z9vpd
2026-05-15 03:04:08 UTC
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2026-05-15 03:04:08 UTCEvent JSON
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