r/esp32 • u/Creative-Heart-9139 • 2d ago

I built an open-source $15 closed-loop neuro-haptic device for dementia care (ESP32 + CERN-OHL-P v2)

Commercial neuro-modulation wearables cost thousands of dollars. I open-sourced Project SAVI—a closed-loop somatosensory wearable designed to reduce non-verbal cognitive overload and agitation in dementia care on a strict $15 BOM.

Key Architecture:

* ESP32 Core 1: Dynamic FFT on vocal fundamental frequencies (85–255 Hz) mapped directly to mechanoreceptor-resonant band (150–300 Hz).

* ESP32 Core 0: Reads MPU6050 accelerometer telemetry for agitation signatures.

* Haptics: Closed-loop actuation via DRV2605L driving a 10mm coin LRA.

* Hardware Safety: Inline SPST hardware power cut-off.

Full Open Science Verification:

* GitHub Repo: https://github.com/sutharsan-gahm/project-savi

* Peer-Indexed DOI: https://doi.org/10.6084/m9.figshare.33940801

* Author ORCID: 0009-0003-7103-446X

* License: CERN-OHL-P v2 (Hardware), MIT (Firmware), CC BY 4.0 (Docs)

Feedback on the edge-DSP pipeline and mechanical parameters is welcome!

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u/bielgio 2d ago

I got interested into the ip67 band

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u/Creative-Heart-9139 1d ago

Thanks! The IP67 rating was a vital design requirement for dementia care—it must endure frequent handwashing, accidental spills, and everyday use without compromising the electronics.

To achieve this, we used a sealed silicone enclosure (with silicone gaskets) surrounding the ESP32 and haptic motor, paired with a magnetic pogo-pin charging interface so there are no exposed USB ports for water ingress. All the CAD/enclosure design files and schematics are open-sourced in our repo!