cart_firmware_added

device_firmware/cart_firmware/tools/analyze.py

@@ -0,0 +1,34 @@
+#!/usr/bin/env python3
+"""Analyze a captured frame: extract pulse timing structure.
+
+Usage: .venv/bin/python tools/analyze.py captures/<name>.npz
+"""
+import sys
+
+import numpy as np
+
+path = sys.argv[1]
+d = np.load(path)
+volts = d["volts"]
+srate = float(d["srate"])
+dt_us = 1e6 / srate
+
+# threshold midway between the two dominant plateaus
+hi_level = np.median(volts)  # idle dominates the frame -> median = idle (high)
+lo_level = np.percentile(volts, 10)
+thr = (hi_level + lo_level) / 2
+bits = (volts > thr).astype(np.int8)
+print(f"levels: high~{hi_level:.2f} low~{lo_level:.2f} thr={thr:.2f} (raw units)")
+
+# run-length encode
+edges = np.flatnonzero(np.diff(bits)) + 1
+starts = np.concatenate(([0], edges))
+ends = np.concatenate((edges, [len(bits)]))
+levels = bits[starts]
+dur_us = (ends - starts) * dt_us
+
+print(f"{len(levels)} runs total")
+print("\nidx level dur_us (first/last runs are idle padding)")
+for i, (lv, du) in enumerate(zip(levels, dur_us)):
+    tag = "H" if lv else "L"
+    print(f"{i:4d} {tag} {du:10.2f}")