A local, cloud-free Bluetooth controller for the discontinued PAIX "BackPAIX" round LED badge — reverse-engineered and rebuilt from scratch.
Made by Makhu Studio · YusufMakhu
The BackPAIX Smart Badge (a 2016 Kickstarter by PAIX Design) is a wearable round LED matrix you controlled from a phone app over Bluetooth. The company shut down and its cloud (AWS + backpaix.com) went dark, so the official app no longer works — leaving the hardware bricked-by-abandonment.
PAIX Control brings it back to life. The BLE protocol was reverse-engineered from the original app, and this is a brand-new controller — 100% local, no cloud, no accounts — that runs as a web app and as a native Android APK.
- 🔌 Connect over Bluetooth and keep the link alive (the badge reverts to its logo on disconnect).
- 🖼️ Built-in patterns (the firmware's emoji ROM) — smile, wink, sun, snow, logo…
- 😄 Full-screen animated emoji faces — wink, blow-kiss, laugh, heart-eyes, blink… (looped natively on-device).
- 🎨 Circular 14×14 pixel editor with outer-ring color — draw your own designs.
- 📝 Scrolling text with a built-in 5×7 font + insertable mini-icons (♥ ★ ☀ …), continuous loop.
- 🎬 Animation library (turn signals, heartbeat, spinner, rain, countdown…) + a frame-by-frame animation editor with timeline.
- 🕒 Clock mode, manual command console.
- 💾 Local save + JSON import/export. 🎨 In-app theme (accent colors + backgrounds).
- 📱 Installable offline Android APK (Capacitor) — or run as a Web Bluetooth PWA in Chrome.
The hardware is a 14×14 monochrome circular LED matrix (~156 pixels) plus a 32-LED color outer ring, driven by a Realtek RTL8762 BLE SoC.
- Commands are written to a single GATT characteristic, chunked into 20-byte fragments.
- A custom image =
2201then23+ ring-color byte + 14×uint16rows. - Animations are native: up to 9 frames are uploaded once (
22 NN+ per-frame durations) and the badge loops them autonomously — no continuous streaming, which would overload its 8051 controller and disconnect.
The full reverse-engineered protocol is documented in PAIX_PROTOCOL.md.
⚠️ Safety: the app only ever writes to the control characteristic19e97635…. The firmware-update (OTA) service0000ffd0…is never touched — writing there could brick the device.
▶️ Live demo (no install): open https://yusufmakhu.github.io/paix-control/paix-web/ in Chrome on Android with your badge nearby. (Web Bluetooth needs a secure context —github.iois HTTPS.)- 📥 Native Android app: download the latest APK — fully offline. Install guide in APK_README.md.
Web (Chrome on Android, or desktop Edge/Chrome): serve the paix-web/ folder over HTTPS (or localhost) and open it — Web Bluetooth requires a secure context.
cd paix-web
python -m http.server 5179 # then open http://localhost:5179 in Chrome/EdgeAndroid APK (offline): see APK_README.md. In short, with Node + the Android SDK:
cd app-android
npm install
npm run build
npx cap sync android
cd android && ./gradlew assembleDebug| Path | What |
|---|---|
paix-web/ |
The app (HTML/JS, no framework): UI, pixel/animation engine, fonts, BLE transport |
paix-web/ble.js |
BLE transport abstraction — Web Bluetooth in the browser, native plugin in the APK |
PAIX_PROTOCOL.md |
Reverse-engineered BLE protocol reference |
paix_test.py |
Python/bleak test harness used during reverse-engineering |
app-android/ |
Capacitor project that wraps paix-web/ into an offline APK |
All the source is here and fully inspectable — there's no analytics, no telemetry, no ads/tracking, and no servers. The app only talks to your badge over Bluetooth; nothing ever leaves your device, and your designs are stored locally (IndexedDB / localStorage). Read the code, it's all here.
This was a labour of love to revive abandoned hardware. If it made you smile, a small tip is welcome — completely optional:
Does the official BackPAIX / PAIX app still work?
No. PAIX Design shut down and its cloud (AWS + backpaix.com) went offline, so the official BackPAIX app no longer works. PAIX Control is a free, independent replacement.
Is this an alternative to the official PAIX / BackPAIX app? Yes — it's a complete, free alternative app for the BackPAIX LED badge, reverse-engineered from the original. Web app + offline Android APK, no cloud, no account.
How do I control my PAIX badge now? Open the web app in Chrome on Android (with your badge nearby), or install the APK. Then connect over Bluetooth and use the gallery, pixel editor, animated emojis or scrolling text.
Does it work on iPhone? Web Bluetooth isn't available on iOS, so use Android (Chrome or the APK).
Is it safe / free? Free and source-available — no analytics, no tracking, no servers. It only talks to your badge over Bluetooth.
Independent, non-commercial interoperability project for hardware you own. Not affiliated with or endorsed by PAIX Design. This repository contains only original work — it does not redistribute the official app's code, binaries, or assets.
Personal-use license © 2026 Makhu Studio (YusufMakhu) — sole owner. Free for personal, non-commercial use; sharing it free of charge is welcome and donations are appreciated. Selling, reselling or any commercial use is NOT permitted — that right is reserved exclusively to the owner. See LICENSE.