fix: add README

Author: schollz

README.md

@@ -269,6 +269,14 @@ Do *not* use these cards! They may appear to work, but they can cause spurious g
 - PNY Elite
 - MicroCenter
 
+#### Writing new SD Cards
+
+```
+sudo parted /dev/sdd --script mklabel gpt mkpart primary fat32 4MiB 100%
+sudo mkfs.fat -F 32 -s 128 -S 512 /dev/sdd1
+sudo partclone.fat32 -r -s sdcard_ectocore.img -o /dev/sdd1 --force
+```
+
 # license
 
 - Apache License 2.0 for no-OS-FatFS (Copyright 2021 Carl John Kugler III)

dev/analyze_sdcards6.py

@@ -0,0 +1,96 @@
+#!/usr/bin/env -S uv --quiet run --script
+# /// script
+# requires-python = ">=3.13"
+# dependencies = [
+#     "numpy",
+#     "plotly",
+#     "click",
+# ]
+# ///
+import glob
+import os
+import click
+import numpy as np
+import plotly.graph_objects as go
+import plotly.io as pio
+
+pio.renderers.default = "browser"
+
+
+def parse_line(line):
+    if b"sdcard" not in line:
+        return None
+    parts = line.split(b"sdcard", 1)
+    fields = parts[1].split()
+    if len(fields) != 5:
+        return None
+    try:
+        return float(fields[0])
+    except:
+        return None
+
+
+def parse_file(fname):
+    vals = []
+    with open(fname, "rb") as f:
+        for line in f:
+            c = parse_line(line)
+            if c is not None:
+                vals.append(c)
+    return np.array(vals)
+
+
+def extract_label(fname):
+    base = os.path.basename(fname)
+    return base[:-4] if base.endswith(".txt") else base
+
+
+@click.command()
+@click.argument("folder", type=click.Path(exists=True))
+def main(folder):
+    folder = os.path.abspath(folder)
+    fnames = sorted(glob.glob(os.path.join(folder, "*.txt")))
+    data = {}
+
+    for fname in fnames:
+        arr = parse_file(fname)
+        if len(arr):
+            data[extract_label(fname)] = arr
+
+    if not data:
+        return
+
+    labels = list(data.keys())
+    xs = []
+    ys = []
+
+    for label in labels:
+        arr = data[label]
+        xs.extend([label] * len(arr))
+        ys.extend(arr)
+
+    fig = go.Figure()
+    fig.add_trace(
+        go.Box(
+            x=xs,
+            y=ys,
+            boxpoints="all",
+            jitter=0.3,
+            pointpos=-1.8,
+            marker=dict(size=3),
+        )
+    )
+
+    fig.update_layout(
+        title="CPU Utilization",
+        yaxis=dict(title="cpu"),
+        xaxis=dict(title="File", tickangle=-45),
+        showlegend=False,
+        height=600,
+    )
+
+    fig.show()
+
+
+if __name__ == "__main__":
+    main()