E2.1 — A real transient produces a candidate

[liversedge]

Epic: E2 — Acoustic detection on real hardware
Release: v1 · Layer: Platform · Blocked on: phone

The microphone runs, and a real club strike mints a Shot.

Components

• AVAudioSession .measurement, AGC/EQ/NS off, small IO buffer — written, never run
• AVAudioTime → capture timebase conversion — written, never run
• Sample-index onset refinement — written, never run

Exit criterion

A real club strike at a real mat mints a Shot with an honest instant.

Requirements

REQ-MIC-1, REQ-MIC-2

---

_{Scope: delivery-scope.md · Requirements: traceability.md · PRD: capture-companion-requirements.md · Conformance: ppcp-conformance.md}

[liversedge]

Named as MVP-critical, 28 August 2026 — and it had no place in the plan

An audit of mvp-online.md against the board found this level uncovered. Requirement (c) is "after every shot and every candidate, the data reaches Studio" — and E2 is mentioned nowhere in that document: not in §1's requirement table, not in §6's order, not in the demo's step 5, which says "Hit a ball. Within a second: candidate on control, then shot…" and assumes this level works.

⛔ It has never run against a real range. AVAudioSession .measurement with AGC/EQ/NS off, the AVAudioTime → capture-timebase conversion, and the sample-index onset refinement are all written, never run — this issue's own component list says so, and nothing has changed that.

⚠ What the hardware runs so far do and do not tell us. #98 and #103 were both found because candidates were being minted on a device — so the path is not dead. ⛔ But neither says a club strike produced them rather than a door, a voice or the mat itself, and neither says the instant was honest. That is this level's exit criterion and it is untouched.

Now scheduled: added to hardware-run-2026-08-27.md as test 6a, and sequenced in mvp-online.md §6 between the hardware run and shots crossing. ⚠ It needs no extra session — tests 3, 5 and 6 already hit balls. What is missing is recording the answer while someone is there, plus a count of Candidates against a count of actual swings, which is the number #22 will need and nobody has.

[liversedge]

Scheduled as test 6a in hardware-run-2026-08-27.md — 8daed9f, pushed.

⚠ It needs no extra session. Tests 3, 5 and 6 already hit balls; what is missing is recording the answer to this level's own question while someone is there, plus a count of Candidates against a count of actual swings — the number #22 will need and nobody has.