---
phase: 11.1-proximity-sensor-app-compatibility-fix
plan: 02
subsystem: driver
tags: [openvr, steamvr, proximity, background-app, cmake]

# Dependency graph
requires:
  - phase: 11.1-01
    provides: "Driver probe_proximity and test_handle commands for coordinated spike testing"
provides:
  - "beyond_spike_monitor.exe OpenVR background client for observing proximity state changes"
  - "Three-signal proximity monitoring (ActivityLevel, ButtonPressed, UserInteraction events)"
affects: [11.1-03, proximity-spike-testing]

# Tech tracking
tech-stack:
  added: []
  patterns: ["OpenVR VRApplication_Background client for passive monitoring"]

key-files:
  created:
    - src/spike/proximity_monitor.cpp
  modified:
    - CMakeLists.txt

key-decisions:
  - "Single-file console app with no dependencies beyond OpenVR SDK"

patterns-established:
  - "OpenVR client apps use POST_BUILD copy of openvr_api.dll (driver DLL does not need it)"

requirements-completed: [SPIKE-03]

# Metrics
duration: 2min
completed: 2026-03-26
---

# Phase 11.1 Plan 02: Companion Monitor App Summary

**OpenVR background client (beyond_spike_monitor.exe) monitoring HMD proximity via ActivityLevel, ButtonPressed bit 31, and UserInteraction events**

## Performance

- **Duration:** 2 min
- **Started:** 2026-03-26T19:53:55Z
- **Completed:** 2026-03-26T19:55:42Z
- **Tasks:** 2
- **Files modified:** 2

## Accomplishments
- Created proximity_monitor.cpp with three independent proximity signal monitors
- Added CMake target with openvr_api.dll runtime copy for client-side execution
- Build succeeds for all targets (driver DLL, beyond_prox_ctl, beyond_spike_monitor)

## Task Commits

Each task was committed atomically:

1. **Task 1: Create proximity_monitor.cpp companion app source** - `0a3d5b7` (feat)
2. **Task 2: Add CMake target and build companion app** - `14f3b9c` (feat)

## Files Created/Modified
- `src/spike/proximity_monitor.cpp` - OpenVR background client monitoring HMD proximity via 3 signals
- `CMakeLists.txt` - Added beyond_spike_monitor target with openvr_api.dll POST_BUILD copy

## Decisions Made
None - followed plan as specified

## Deviations from Plan
None - plan executed exactly as written.

## Issues Encountered
None

## User Setup Required
None - no external service configuration required.

## Next Phase Readiness
- beyond_spike_monitor.exe built and ready for coordinated spike testing
- Can be run alongside SteamVR to observe proximity state changes from driver's probe_proximity and test_handle commands

## Self-Check: PASSED

- FOUND: src/spike/proximity_monitor.cpp
- FOUND: beyond_spike_monitor.exe (build output)
- FOUND: openvr_api.dll (build output)
- FOUND: commit 0a3d5b7
- FOUND: commit 14f3b9c

---
*Phase: 11.1-proximity-sensor-app-compatibility-fix*
*Completed: 2026-03-26*