RWfit rings¶

PulseLoop implements the RWfit protocol in Swift; it does not bundle the vendor SDK. RwFit rings use the A00A service, B002 write characteristic and B003 notification characteristic. Rebranded model names alone are not reliable protocol identifiers.

Compatibility status¶

Hardware validation is pending for SR16 and SY01. Reports from PulseLoop 2.6.0 included pairing without data and manual-reading timeouts. The supplied SR16 export (firmware 001.0B) contains connection and sync-stage logs, but no raw packets. Its approximately six-second stage changes match the old timeout-based pager; “done” in that export is not evidence of a successful history transfer.

The fixes have SDK-derived regression coverage. They do not establish universal compatibility with every ring sold for the RwFit app.

Protocol references¶

Modern behavior follows the published SDK. Legacy 7E support retains the older vendor-app-derived layouts. OTA sibling services are framing hints; a validated response establishes the protocol. With no modern hint, a bounded legacy identity read precedes an attempt at modern initialization.

Initialization and responses¶

Modern frames are AB flag lengthBE crc16ARC payload. The payload starts with command, key, and operation bytes. 01 responses require an echoed-triple 11 ACK; 11 replies can carry data and are not acknowledged. 21 pushes carry unsolicited data and never complete a pending transaction. The parser supports split headers, continuations and coalesced frames with an 8 KiB payload limit.

Initialization runs in order: 0302 session setup, 0202 timezone (signed quarter hours and iOS platform 01), 0201 clock, then 0263 function menu. Password-capable rings require 0304 authentication using the SDK default 0000. Authentication failure is reported without resetting the password. History and manual actions remain unavailable until initialization succeeds.

Capabilities come from the function menu, not from the presence of an OTA service. Commands wait for GATT transmission confirmation and a matching response; modern transactions allow five seconds per response attempt and two retries.

History and manual measurements¶

Only supported streams are queried. Modern history is requested repeatedly until an explicit empty page; timers do not turn an unanswered request into success. Current-day steps (051A) and historical steps (0502) are reconciled through the existing cumulative/bucket persistence paths.

Sync consumes transferred history from the ring. Non-sleep streams are deleted only after the complete response has been validated and durably imported. Sleep requires deletion after each page, so raw pages are first atomically saved to a bounded, per-device journal in Application Support. Complete sleep sessions are assembled and imported before removing that journal. It survives interruption and is cleared with the user's app data. RwFit may no longer be able to import records that PulseLoop has consumed.

Live values arrive on 02-group commands: HR 0224, SpO2 024E, HRV 0269, BP 0231, temperature 0230, stress 024F, and glucose 026C. 0609 is measurement status, never a reading: raw status zero means completion; other vendor statuses are retained as diagnostics because their meanings are undocumented. A measurement pauses history at a page boundary; stop must complete before history resumes.

Successful empty sync, imported data, partial import, failure and cancellation are separate outcomes. Only successful completion updates successful-sync freshness. The greeting “Burning the midnight oil” follows phone time and is unrelated to BLE.

Tester verification¶

On SR16 and SY01, verify initial connection and populated history, HR and SpO2 spot readings, reconnect, and sync interrupted mid-transfer. Record firmware and whether the same ring works in RwFit. Enable Privacy & Data → Diagnostics → raw packet capture before reproducing, then export diagnostics. Raw health packets remain opt-in in release builds; protocol stages and failures are logged normally.