IdeaWell

Project ideas from Hacker News discussions.

I Connected My Withings Body+ to Home Assistant with an ESP32

Original Article

Hacker News Discussion

📝 Discussion Summary (Click to expand)

Theme 1 – Offline/local control via ESP32 Bluetooth proxies
Many commenters highlight using an ESP32 as a Bluetooth bridge to talk directly to devices like Withings scales, Eufy scales, or thermometers, bypassing vendor clouds and apps.
- “If you have a eufy scale, you can do this with no LLM needed - just set up an esp32 Bluetooth proxy, add it to home assistant, and then use the EufyLife integration…” — dgacmu
- “I actually found this out by accident… saw eufy show up as an option and was like wait what?” — dawnerd
- “The interesting thing here is the opportunity to make a sdk for interfacing with the Withings hardware offline.” — variety8675

Theme 2 – AI‑assisted reverse engineering of undocumented Bluetooth protocols
Several users describe using LLMs (Claude Opus, etc.) to deconstruct proprietary Bluetooth communications, enabling custom apps or Home Assistant integrations without deep reverse‑engineering expertise.
- “Using AI to reverse engineer undocumented Bluetooth protocols has been a godsend for me.” — AshleyGrant
- “I threw the APK at Claude Opus… I now no longer have to use their terrible app… I can either use the custom‑built Android app… or the Home Assistant app I built using AI.” — AshleyGrant
- “Just to be pedantic, was it reverse engineered? Or did it just extract it out of the apk?” — Neywiny (prompting AshleyGrant’s clarification)

Theme 3 – Demand for open code / frustration over missing implementations
A recurring sentiment is that articles or claims without shared code feel like empty bragging; participants want repositories, SDKs, or firmware to verify and build upon the work.
- “How can you write (or have AI write) such an article without also sharing the code? Now it’s just a pretty useless brag, ‘look what I built’.” — kjmr
- “If the AI wrote the article, and with no code, how do we know this even happened?” — SaberTail
- “Regarding the code for this project I will upload it soon…” — sabatesduran
- “Withings has a full available API…” — bassdreads (showing appetite for accessible interfaces)

🚀 Project Ideas

Withings Offline SDK & ESPHome Generator

Summary

  • Provides a lightweight Python/TypeScript library that communicates directly with Withings scales and watches via BLE, bypassing the cloud.
  • Generates ready-to-use ESPHome YAML snippets and Home Assistant integrations for automatic weight/sleep data logging.

Details

Key Value
Target Audience DIY smart home enthusiasts, Withings owners wanting offline data, Home Assistant users
Core Feature BLE client that reads Withings GATT services, parses measurement payloads, outputs JSON/MQTT, and emits ESPHome config
Tech Stack Python (bleak) or Node (noble) for BLE, Jinja2/templates for YAML generation, optional Rust for performance
Difficulty Medium
Monetization Hobby

Notes

  • HN user variety8675 noted: "The interesting thing here is the opportunity to make a sdk for interfacing with the Withings hardware offline." – this directly fulfills that request.
  • User sabatesduran wanted a tool to generate person IDs and YAML; the SDK includes CLI commands to do exactly that.
  • Enables discussion on BLE security, open‑source health data ownership, and spurs further integrations (e.g., Garmin, Apple Health).

APK-to-BLE Protocol Reverse Engineering Assistant

Summary

  • Upload an Android APK; the tool uses LLMs to decompile, extract Bluetooth GATT characteristics, and produce human-readable protocol documentation plus starter code for Home Assistant or custom apps.
  • Solves the frustration of manually reverse engineering undocumented Bluetooth devices (e.g., BMPro RV system, Withings, etc.) and provides verifiable proof of AI‑derived specs.

Details

Key Value
Target Audience Tinkerers, reverse engineers, Home Assistant integrators, developers building custom BLE apps
Core Feature Automated APK analysis pipeline (jadx/decompiler + LLM) that outputs BLE service/characteristic map, sample Python/JS code, and optional patch generation
Tech Stack Python backend (Jadx, LLM API), frontend React/Vue for upload/results, Docker for isolation
Difficulty High
Monetization Revenue-ready: subscription for private APK processing (free tier for open-source APKs)

Notes

  • AshleyGrant said AI reverse engineering was a "godsend" for controlling an RV system; this tool would make that process repeatable and transparent.
  • SaberTail questioned proof of AI work; the assistant provides decompiled source traces and protocol specs, addressing skepticism.
  • Neywiny distinguished reverse engineering from extraction – the tool clearly labels each step, enabling trustworthy outputs.
  • Sparks debate on legality/ethics of APK scraping while providing a valuable utility for legitimate interoperability.

Universal ESP32 BLE Proxy Hub for Health Devices

Summary

  • A pluggable ESP32‑based firmware that acts as a BLE‑to‑MQTT/Home Assistant gateway, with built‑in drivers for popular health/scales (Eufy, Withings, Garmin, Xiaomi) and a web UI to add new devices via simple config.
  • Addresses the need for a reliable, local‑only bridge that avoids cloud sync and phone apps, as highlighted by users integrating scales via ESP32 proxies.

Details

Key Value
Target Audience Home Assistant users, Quantified Self enthusiasts, anyone frustrated with proprietary health apps
Core Feature ESP32 firmware scanning for known BLE advertisements, connecting, parsing measurements, publishing to MQTT/Home Assistant; web configurator for mapping attributes
Tech Stack ESP‑IDF or Arduino ESP32 core (with optional ESPHome base), custom components for each device, configurator using Flask or Node‑RED
Difficulty Medium
Monetization Hobby (open‑source firmware; optional pre‑flashed hardware kits sold separately)

Notes

  • dgacmu praised his Eufy scale integration via an ESP32 Bluetooth proxy, saying it "works fantastically."
  • dawned discovered BLE proxy capability accidentally when his combustion thermometer appeared, showing demand for a generic solution.
  • Users expressed desire for a polished plug‑in (e.g., "athome brand" smart plug); this project provides the firmware foundation for such a product.
  • Encourages discussion on BLE standardization, local‑only health data pipelines, and extending support to emerging devices.

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