Closed loop test suite, vibe coded, needs some refinement.

README.md

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+# Closed Loop Audio Test Suite
+
+Simple Python-based testing system for PCB audio hardware validation.
+
+## Features
+
+- **Automated Testing**: Latency, THD, and SNR measurements across multiple frequencies
+- **Metadata Tracking**: PCB version, revision, software version, timestamps, notes
+- **YAML Output**: Human-readable structured results
+- **Simple Workflow**: Run tests, view results, compare versions
+
+## Quick Start
+
+### 1. Install Dependencies
+
+```bash
+pip install -r requirements.txt
+```
+
+### 2. Run a Test
+
+```bash
+python run_test.py \
+  --pcb-version "v2.1" \
+  --pcb-revision "A" \
+  --software-version "a3f2b1c" \
+  --notes "Replaced capacitor C5"
+```
+
+### 3. View Results
+
+```bash
+# View specific test
+python view_results.py test_results/20260226_123456_results.yaml
+
+# List all tests
+python view_results.py --list
+
+# View latest test
+python view_results.py test_results/*.yaml | tail -1
+```
+
+## Test Metrics
+
+- **Latency**: Round-trip delay between input and output channels (ms)
+- **THD**: Total Harmonic Distortion for input and output (%)
+- **SNR**: Signal-to-Noise Ratio for input and output (dB)
+
+Tests run at multiple frequencies: 100 Hz, 250 Hz, 500 Hz, 1 kHz, 2 kHz, 4 kHz, 8 kHz
+
+## Output Format
+
+Results are saved as YAML files in `test_results/`:
+
+```yaml
+metadata:
+  test_id: 20260226_123456
+  timestamp: '2026-02-26T12:34:56.789012'
+  pcb_version: v2.1
+  pcb_revision: A
+  software_version: a3f2b1c
+  notes: Replaced capacitor C5
+test_results:
+  - frequency_hz: 1000
+    latency_ms: 2.345
+    thd_input_percent: 0.012
+    thd_output_percent: 0.034
+    snr_input_db: 92.5
+    snr_output_db: 89.2
+```
+
+## Configuration
+
+Edit `config.yaml` to customize:
+- Audio device settings
+- Test frequencies
+- Test duration
+- Output options
+
+## Hardware Setup
+
+```
+Laptop <-> Audio Interface (Scarlett) <-> DUT <-> Audio Interface (Scarlett) <-> Laptop
+         Output Channels 1&2         Input Channels 1&2
+```
+
+The system auto-detects Focusrite Scarlett audio interfaces.
+
+## File Structure
+
+```
+closed_loop_audio_test_suite/
+├── config.yaml              # Test configuration
+├── run_test.py              # Main test runner
+├── view_results.py          # Results viewer
+├── src/
+│   └── audio_tests.py       # Core test functions
+└── test_results/            # YAML output files
+    └── YYYYMMDD_HHMMSS_results.yaml
+```
+
+## Tips
+
+- Each test run creates a timestamped YAML file
+- Results are self-contained with full metadata
+- Compare tests by opening multiple YAML files
+- Archive old tests by moving YAML files to subdirectories