HealthTracking/README.md

Design system · Literature notes · Issues

The BLE parser decoding one Heart Rate Measurement packet (flags 0x16: skin contact detected, one RR interval). It is plain TypeScript, so Node runs it straight from a fresh clone, no install:

$ node --experimental-strip-types --no-warnings --input-type=module -e "import { parseHeartRateMeasurement as parse } from './src/ble/heartRateParser.ts'; console.log(parse([0x16, 0xA0, 0x6C, 0x01]))"
{
  bpm: 160,
  contactSupported: true,
  contactDetected: true,
  energyExpended: null,
  rrIntervalsMs: [ 355.46875 ]
}

What it is

FightRate (repository HealthTracking) is an Android app that records heart rate continuously from a Bluetooth Low Energy chest strap during combat-sport training. It is a bare React Native app (no Expo): a Kotlin foreground service owns the BLE connection and stores every timestamped BPM sample in SQLite, and the React Native UI reads those samples. UI copy is PT-BR; code identifiers are English.

Tab	What it does
Capture	Live BPM, average / peak / sample-count tiles, BLE, battery and background status, and the training chart. Start/stop marks a training window inside the continuous stream; monitoring keeps storing samples either way
History	Saved training windows and continuous-usage blocks (split by gaps), each with average / peak / min BPM; open one to inspect the timestamped data; custom time range
Sensor	BLE scan, device list, connect, connection phase, signal (RSSI), battery level, BLE services/characteristics diagnostics and a shortcut to Android battery-optimization settings
Insights	Current/average BPM, range, variability, time in zones, load, heart-rate drift, post-session recovery, HRmax/HRR (marked as needing a profile) and HRV (only when the strap sends RR intervals)

Why use it

• Real data only. Every number on screen is computed from samples a real sensor sent. With no samples the app shows an empty state instead of inventing a peak, zone, load or HRV. Samples outside 30–240 bpm, or reported without skin contact, are discarded.
• Capture survives the screen turning off. It runs in a foreground service of type connectedDevice, restarts as START_STICKY, reconnects with backoff (2 s → 5 s → 10 s → 30 s) and restores the last device after a restart.
• Built for rounds, not steps. Fixed zones BASE <150, PRESSÃO 150–169, REDLINE 170+, and a zoomable chart (pinch zoom, pan, tap-to-pin) whose ticks follow the visible span, from half-second to one-minute steps.

Do not use it if you need iOS (there is no native capture module there), zones from your own HRmax or resting heart rate (there is no athlete profile yet), or a signed build you can distribute (see Project status).

How it works

1. BLE client: FightRateCaptureService.kt scans, connects by known device id, subscribes to Heart Rate Measurement 2A37 (service 180D), reads Battery Level 2A19 and RSSI. After 12 s without a valid sample it reports a stale state and waits for new real data.
2. Parser: HeartRateMeasurementParser.kt and src/ble/heartRateParser.ts read UInt8/UInt16 BPM, skin contact and RR intervals (converted from 1/1024 s to ms).
3. Storage: FightRateCaptureStore.kt writes fightrate_rn_capture.db (schema version 2) with training windows and continuous samples (timestamp, BPM, contact, RR intervals, device).
4. Bridge: FightRateCaptureModule.kt and src/native/FightRateCaptureNative.ts expose start/stop, connect, snapshots and samples, and turn service broadcasts into JS events.
5. Domain: pure TypeScript in src/training/ computes metrics, zones, drift, recovery, usage blocks (a 5-minute gap starts a new block) and the chart viewport.
6. UI: a state-driven tab shell in src/app/FightRateApp.tsx (no navigation library), Reanimated 4 + Worklets animations and design tokens in src/theme/.

Design direction: FIGHTRATE_DESIGN_SYSTEM.md (01 — Corner Instrument, the official one). FIGHTRATE_COMBAT_LAB_DESIGN_SYSTEM.md is a deprecated direction kept for history. Specs and plans live in docs/superpowers/.

Quick start

Requirements: Node ≥ 22.11 (engines in package.json), the Android SDK and a JDK.

git clone https://git.evandro.dev.br/evandro/HealthTracking.git
cd HealthTracking
npm install
npm run typecheck
npm test -- --runInBand

npm run start      # Metro
npm run android    # run on a device/emulator

Debug APK:

cd android
./gradlew assembleDebug
# output: android/app/build/outputs/apk/debug/app-debug.apk

Warning

Grant the permissions and exempt the app from battery optimization. The manifest requests Bluetooth scan/connect, fine location, notifications and a foreground service of type connectedDevice. The Bateria button on the Sensor tab opens Android's battery-optimization settings (REQUEST_IGNORE_BATTERY_OPTIMIZATIONS is declared) so background capture isn't throttled.

If Gradle reports No Java compiler found, point JAVA_HOME to the JBR bundled with Android Studio:

export JAVA_HOME="<Android Studio install dir>/jbr"
export PATH="$JAVA_HOME/bin:$PATH"

If React Native autolinking keeps a stale package after renaming Android package paths, clean the generated Gradle caches before rebuilding:

rm -rf android/.gradle android/app/build android/build .gradle
cd android && ./gradlew assembleDebug

Project status

Work in progress: package.json is 0.0.1, Android versionName is 1.0, applicationId is com.healthtracking.fightrate. The last feature work (2026-06-16) shipped the "Instrumento Forte" UI refinement; its record in .impeccable.md lists npm run typecheck with 0 errors, npm test -- --runInBand with 74/74 passing, and npm run lint failing on a pre-existing jest/globals configuration error.

Known limits:

• Android only: capture exists only in the Kotlin native module; the ios/ project has no equivalent.
• No athlete profile yet: zones use the fixed thresholds above; %HRmax zones, Karvonen and full TRIMP are shown as needing a profile. The app doesn't invent HRmax or resting heart rate.
• HRV needs RR intervals: without them the dashboard says so instead of estimating.
• Release signing: the release build type uses the debug keystore (android/app/build.gradle); generate your own keystore before distributing.

The literature notes in docs/data/pesquisa.md state that population tables and formula-based estimates are not a substitute for measured testing.

License

Proprietary license in LICENSE: personal and study use only, with visible credit to the author. Redistribution, resale, sublicensing and commercial use need written authorization; authorized commercial use is by contract, with 50% of gross revenue paid to the author. Provided "as is", without warranty.

Built on React Native, Reanimated, Gesture Handler, react-native-svg, Lucide icons and JetBrains Mono.

_{Made by Evandro Fonseca Junior · git.evandro.dev.br}