v0.2.1 — Local interval log + disconnect/reconnect hardening

Adds an optional local fallback log on the scan screen and hardens the disconnect/reconnect path.

New

• Save intervals to file toggle on the scan screen (off by default). When enabled, every RR/PP value that goes out over LSL is also appended to a text file at Android/data/io.github.abcsds.rrstreamer/files/Documents/<YYYY-MM-DD_HH-MM-SS-MS>.txt — one rounded-ms int per line. A safety net for sessions where the LSL stream isn't recorded over the network. Pull via adb pull, the system Files app, or USB.
• The writer flushes after every line, so a kill never loses more than the in-flight sample. Logger failures (missing SD card, I/O hiccup) are logged and swallowed — they never break the live BLE → LSL pipeline.

Fixed

• FGS ANR after stop+restart: startForeground() is now called in onStartCommand too. With BIND_AUTO_CREATE the service can outlive a stop()+stopSelf(), so a follow-up startForegroundService(...) reaches an existing instance whose onCreate doesn't re-run. Without re-asserting startForeground the 5-second FGS watchdog ANRs.
• UI stuck in Connecting after reconnect: per-session resources (LSL streamer, log file) are now torn down on disconnect/error, not just on stop. Without the streamer close the lazy first-sample init skipped the state transition and the UI stayed on Connecting forever even while samples were flowing.
• 3-frame protocol decision window: the Polar H10 sometimes emits an HR-only 0x2A37 frame before computing the first R-R interval (especially right after reconnect). Committing to PolarPpi on that single frame stranded the client waiting for PPI from a band that doesn't produce it.
• PMD CP error responses parsed: bands like the H10 expose the PMD service but answer START_PPI with NOT_SUPPORTED (error code 3). The app now surfaces a clean error and you can retry, instead of waiting forever for frames that won't arrive.
• Cross-thread session fields use @Volatile + null-then-close so a stop() on the main thread can't race a write-after-close from the BLE binder thread.

Install

Sideload RRStreamer-v0.2.1.apk on Android 8.0+ (API 26+). The package identifier changed in this release, so Android treats this as a different app from earlier builds — uninstall any previous RRStreamer first, otherwise the install will be refused.

v0.2.0 — PPG band support (Polar Verity Sense, OH1)

Adds support for PPG (optical) bands alongside the existing ECG path.

New

• Polar Verity Sense, OH1, OH1+ — bands that don't expose RR over the standard 0x2A37 characteristic. The app picks the right protocol at connect time:
  • If the first 0x2A37 notification carries the RR-flag bit → ECG path (Polar H10, Wahoo TICKR, …) → RR <devicename> outlet.
  • Else if the device exposes the Polar PMD service (FB005C80-…) → bumps MTU to 232, chains the PMD CCCD writes, sends START_PPI → PP <devicename> outlet (peak-to-peak intervals in ms).
• New PP outlet symmetric with RR: Markers, 1 channel, int32, source-id PP_markers_<devicename>.

Notes

• RMSSD computed from PP is shown with a ≈ prefix and an approx qualifier on the 100-beat graph — useful for relative comparisons but not ECG-grade.
• Receivers can resolve by type (Markers) and inspect the stream name to handle either RR or PP transparently.

Install

Sideload RRStreamer-v0.2.0.apk on Android 8.0+ (API 26+).

v0.1.0 — Initial release

First public release of RRStreamer — Android client that streams heart rate and beat-to-beat (RR) intervals from a BLE Heart Rate band to the network as Lab Streaming Layer marker streams.

What it does

• Scans for BLE bands advertising the standard Heart Rate service (0x180D).
• Connects on tap; subscribes to the Heart Rate Measurement characteristic (0x2A37).
• Pushes two LSL outlets:
  • HR <devicename> — heart rate (bpm)
  • RR <devicename> — beat-to-beat intervals in milliseconds (rounded int)
• Foreground service keeps the GATT connection alive when the screen is off.

Supported bands

Any BLE Heart Rate band exposing RR intervals: Polar H10 (tested), Wahoo TICKR, Garmin HRM-Pro, Coospo, Decathlon Kalenji, Suunto Smart Sensor, etc.

Install

Sideload RRStreamer-v0.1.0.apk on Android 8.0+ (API 26+). Allow installs from your browser, then open the file. Tested on Android 15 (API 35).

Verify the stream

On any machine on the same Wi-Fi:

pip install pylsl && python scripts/verify_lsl.py