fix(led-tool): harden Web Serial raw REPL connect

Improve boot wait, readUntil buffer handling, and settings editor
host/Web Serial flows after device reset.

Co-authored-by: Cursor <cursoragent@cursor.com>

README.md

@@ -25,16 +25,36 @@ Connection is always via **`-p` / `--port`** (default `/dev/ttyACM0`). There is
 | `-r`, `--reset` | Reset the device |
 | `-f`, `--follow` | Follow serial output (optional timeout seconds) |
 | `--pause` | Sleep N seconds (for chained actions) |
-| `-u`, `--upload` | Recursive upload: `-u SRC [DEST]` |
+| `-u`, `--upload` | Recursive upload: `-u SRC [DEST]` (skips unchanged files via `file_hashes.json` on device) |
-| `--src`, `--lib` | Upload `src/` or a tree to `/lib` |
+| `--src`, `--lib`, `--all` | Deploy led-driver trees to flash root, `patterns/`, and `lib/` |
-| `-e` | Erase device code (keeps `settings.json`) |
+| `--force-upload` | Upload every file; ignore `file_hashes.json` |
+| `-e`, `--erase` | Erase everything at device root (including `settings.json` and `presets.json`) |
 | `--rm` | Remove a path on the device |
 | `--flash` | Flash a firmware binary (uses **esptool** on the host) |
 
-**Default behaviour:** the tool always downloads `settings.json`, prints the merged view, and uploads again **only** when you pass setting edits (`--name`, `--leds`, …), **`--preset`**, or the relevant upload/flash/erase actions in order.
+**Settings I/O:** With no arguments, **`led-cli`** prints help (no device access). **`--show`** downloads `settings.json` and prints it (read-only). Setting fields (`--name`, `-b`, …) download once, merge, print, and **upload only when a value actually changed**. **`--preset`** alone only touches **`presets.json`** (no `settings.json` download). Ordered actions (`--reset`, `--upload`, `-e`, …) run without touching settings unless you also pass **`--show`** or setting / preset edits as above.
 
 Run **`python cli.py -h`** for the full epilog and argument list.
 
+## Web UI (`static/` + `web.py`)
+
+Edit **`settings.json`** in the browser:
+
+- **Web Serial** — USB on the machine running the browser (Chrome/Edge). Use **Connect USB**, then **Download** / **Upload**.
+- **Host serial** — USB on the Pi/PC running **`led-cli`** (port list + **`led-cli`** merge/upload).
+
+**Standalone (Flask):**
+
+```bash
+cd led-tool
+python web.py
+# open http://<host>:5000/editor
+```
+
+**Embedded in led-controller:** open **LED Tool** in the main UI, or visit **`/led-tool/editor`**.
+
+Legacy Flask form UI remains at **`/`** on port 5000; prefer **`/editor`** for Web Serial support.
+
 ## License
 
 See **LICENSE** in this directory.

cli.py

@@ -2,8 +2,10 @@
 """
 LED Bar Configuration CLI Tool
 
-Command-line interface for downloading, editing, and uploading settings.json
+Command-line interface for editing settings.json on MicroPython devices via mpremote.
-to/from MicroPython devices via mpremote.
+Settings are downloaded from the device only when displaying (--show) or when applying
+setting changes; uploads occur only when something changed. Use --erase to clear the
+device filesystem (including settings).
 """
 
 import json
@@ -221,6 +223,10 @@ def _get_ordered_actions(argv: List[str]) -> List[tuple]:
             actions.append(('upload', ["lib", "lib"]))
             i += 1
             continue
+        if arg == '--force-upload':
+            # Handled via argparse; skip during action scan
+            i += 1
+            continue
         if arg == '--lib':
             # Upload local DIR (default: ./lib) to /lib on device
             local_dir = "lib"
@@ -279,10 +285,13 @@ def main() -> None:
         formatter_class=argparse.RawDescriptionHelpFormatter,
         epilog="""
 Examples:
-  # Download and print current settings
+  # Show help (no device I/O)
   %(prog)s
 
-  # Download, edit device name and brightness, then upload
+  # Show current settings.json from device (read-only)
+  %(prog)s --show
+
+  # Edit device name and brightness, then upload only if values changed
   %(prog)s -n "LED-Strip-1" -b 128
 
   # Set multiple parameters
@@ -481,6 +490,12 @@ Examples:
         help="Upload ./src (excluding patterns), ./src/patterns, and ./lib."
     )
 
+    parser.add_argument(
+        "--force-upload",
+        action="store_true",
+        help="Upload every file; ignore file_hashes.json on the device",
+    )
+
     parser.add_argument(
         "--patterns", "--paterns",
         dest="patterns_dir",
@@ -500,7 +515,7 @@ Examples:
         "-e", "--erase",
         dest="erase_all",
         action="store_true",
-        help="Erase all code on the device (delete all files except settings.json)"
+        help="Erase the device filesystem: delete all files and directories at device root (including settings.json and presets.json)",
     )
 
     parser.add_argument(
@@ -516,6 +531,9 @@ Examples:
     )
 
     try:
+        if len(sys.argv) <= 1:
+            parser.print_help()
+            return
         args = parser.parse_args()
         ordered_actions = _get_ordered_actions(sys.argv)
     except ValueError as e:
@@ -579,8 +597,14 @@ Examples:
                 else:
                     print(f"Uploading {upload_dir} to device on {port}...", file=sys.stderr)
                 conn = DeviceConnection(port)
-                files_copied, dirs_created = conn.upload_directory(upload_dir, remote_dir)
+                files_copied, dirs_created, files_skipped = conn.upload_directory(
-                print(f"Upload complete: {files_copied} files, {dirs_created} directories created.", file=sys.stderr)
+                    upload_dir, remote_dir, force=args.force_upload
+                )
+                print(
+                    f"Upload complete: {files_copied} uploaded, {files_skipped} skipped, "
+                    f"{dirs_created} directories created.",
+                    file=sys.stderr,
+                )
             except Exception as e:
                 print(f"Error uploading directory: {e}", file=sys.stderr)
                 sys.exit(1)
@@ -608,9 +632,12 @@ Examples:
                         file=sys.stderr,
                     )
                     conn = DeviceConnection(port)
-                    files_copied, dirs_created = conn.upload_directory(temp_src, "")
+                    files_copied, dirs_created, files_skipped = conn.upload_directory(
+                        temp_src, "", force=args.force_upload
+                    )
                     print(
-                        f"Upload complete: {files_copied} files, {dirs_created} directories created.",
+                        f"Upload complete: {files_copied} uploaded, {files_skipped} skipped, "
+                        f"{dirs_created} directories created.",
                         file=sys.stderr,
                     )
             except Exception as e:
@@ -631,14 +658,12 @@ Examples:
 
         elif action_name == 'erase_all':
             try:
-                print(f"Erasing all code on device {port}...", file=sys.stderr)
+                print(f"Erasing device filesystem on {port}...", file=sys.stderr)
                 conn = DeviceConnection(port)
                 items = conn.list_files('')
                 for name, is_dir, size in items:
-                    if name == "settings.json":
-                        continue
                     conn.delete(name)
-                print("Erase complete.", file=sys.stderr)
+                print("Erase complete (device root is empty).", file=sys.stderr)
             except Exception as e:
                 print(f"Error erasing device: {e}", file=sys.stderr)
                 sys.exit(1)
@@ -735,40 +760,86 @@ Examples:
         # Clamp into single-byte range; store as int in settings.json
         edits["id"] = max(0, min(255, args.device_id))
 
-    # 1. Download: get current settings from device
+    settings_work = args.show or bool(edits)
-    try:
+
-        print(f"Downloading settings from {args.port}...", file=sys.stderr)
+    if settings_work:
-        settings = download_settings(args.port)
+        try:
-        print("Settings downloaded successfully.", file=sys.stderr)
+            print(f"Downloading settings from {args.port}...", file=sys.stderr)
-    except Exception as e:
+            settings = download_settings(args.port)
-        if "timeout" in str(e).lower() or "connection" in str(e).lower():
+            print("Settings downloaded successfully.", file=sys.stderr)
-            print(f"Error: Connection timeout. Check device connection on {args.port}", file=sys.stderr)
+        except Exception as e:
-        else:
+            if "timeout" in str(e).lower() or "connection" in str(e).lower():
-            print(f"Error downloading settings: {e}", file=sys.stderr)
+                print(
-        sys.exit(1)
+                    f"Error: Connection timeout. Check device connection on {args.port}",
+                    file=sys.stderr,
+                )
+            else:
+                print(f"Error downloading settings: {e}", file=sys.stderr)
+            sys.exit(1)
+
+        if args.show:
+            print_settings(settings)
+            if not edits and args.preset is None:
+                return
+
+        changed_edits: Dict[str, Any] = {}
+        for key, value in edits.items():
+            if settings.get(key) != value:
+                changed_edits[key] = value
+
+        if edits and not changed_edits:
+            print("No settings changes detected; skipping settings upload.", file=sys.stderr)
+
+        if changed_edits:
+            print(f"Applying {len(changed_edits)} setting change(s)...", file=sys.stderr)
+            settings.update(changed_edits)
 
-    # If --show only, print and exit (unless presets or settings are being written)
-    if args.show:
         print_settings(settings)
-        if not edits and args.preset is None:
-            return
 
-    # 2. Edit: only apply/upload settings when values actually change
+        if args.preset is not None:
-    changed_edits: Dict[str, Any] = {}
+            pattern = args.pattern if args.pattern is not None else "on"
-    for key, value in edits.items():
+            try:
-        if settings.get(key) != value:
+                print(f"Downloading presets from {args.port}...", file=sys.stderr)
-            changed_edits[key] = value
+                presets_data = download_presets(args.port)
+                entry = presets_data.get(args.preset)
+                if not isinstance(entry, dict):
+                    entry = {}
+                entry["p"] = pattern
+                presets_data[args.preset] = entry
+                print(
+                    f"Writing preset {args.preset!r} (pattern={pattern}) to {PRESETS_REMOTE}...",
+                    file=sys.stderr,
+                )
+                upload_presets(args.port, presets_data, reset=not bool(edits))
+                print("Presets uploaded successfully.", file=sys.stderr)
+                if not edits:
+                    print("Device will reset.", file=sys.stderr)
+            except Exception as e:
+                if "timeout" in str(e).lower() or "connection" in str(e).lower():
+                    print(
+                        f"Error: Connection timeout. Check device connection on {args.port}",
+                        file=sys.stderr,
+                    )
+                else:
+                    print(f"Error uploading presets: {e}", file=sys.stderr)
+                sys.exit(1)
 
-    if edits and not changed_edits:
+        if changed_edits:
-        print("No settings changes detected; skipping settings upload.", file=sys.stderr)
+            try:
+                print(f"\nUploading settings to {args.port}...", file=sys.stderr)
+                upload_settings(args.port, settings)
+                print("Settings uploaded successfully. Device will reset.", file=sys.stderr)
+            except Exception as e:
+                if "timeout" in str(e).lower() or "connection" in str(e).lower():
+                    print(
+                        f"Error: Connection timeout. Check device connection on {args.port}",
+                        file=sys.stderr,
+                    )
+                else:
+                    print(f"Error uploading settings: {e}", file=sys.stderr)
+                sys.exit(1)
+        return
 
-    if changed_edits:
-        print(f"Applying {len(changed_edits)} setting change(s)...", file=sys.stderr)
-        settings.update(changed_edits)
-
-    print_settings(settings)
-
-    # 3a. Presets file (led-driver presets.json)
     if args.preset is not None:
         pattern = args.pattern if args.pattern is not None else "on"
         try:
@@ -783,29 +854,24 @@ Examples:
                 f"Writing preset {args.preset!r} (pattern={pattern}) to {PRESETS_REMOTE}...",
                 file=sys.stderr,
             )
-            upload_presets(args.port, presets_data, reset=not bool(edits))
+            upload_presets(args.port, presets_data, reset=True)
             print("Presets uploaded successfully.", file=sys.stderr)
-            if not edits:
+            print("Device will reset.", file=sys.stderr)
-                print("Device will reset.", file=sys.stderr)
         except Exception as e:
             if "timeout" in str(e).lower() or "connection" in str(e).lower():
-                print(f"Error: Connection timeout. Check device connection on {args.port}", file=sys.stderr)
+                print(
+                    f"Error: Connection timeout. Check device connection on {args.port}",
+                    file=sys.stderr,
+                )
             else:
                 print(f"Error uploading presets: {e}", file=sys.stderr)
             sys.exit(1)
+        return
 
-    # 3b. Settings upload (resets device)
+    if ordered_actions:
-    if changed_edits:
+        return
-        try:
+
-            print(f"\nUploading settings to {args.port}...", file=sys.stderr)
+    parser.print_help()
-            upload_settings(args.port, settings)
-            print("Settings uploaded successfully. Device will reset.", file=sys.stderr)
-        except Exception as e:
-            if "timeout" in str(e).lower() or "connection" in str(e).lower():
-                print(f"Error: Connection timeout. Check device connection on {args.port}", file=sys.stderr)
-            else:
-                print(f"Error uploading settings: {e}", file=sys.stderr)
-            sys.exit(1)
 
 
 if __name__ == "__main__":

deploy_manifest.py

@@ -0,0 +1,45 @@
+"""
+Host-side helpers for file_hashes.json (same format as led-driver/src/file_hashes.py).
+"""
+
+import hashlib
+import json
+import os
+
+MANIFEST_VERSION = 1
+MANIFEST_FILENAME = "file_hashes.json"
+HASH_ALGO = "sha256"
+
+
+def normalize_remote_path(remote_file: str) -> str:
+    """Device-relative path with forward slashes (no leading slash)."""
+    return remote_file.replace("\\", "/").lstrip("/")
+
+
+def sha256_hex_file(path: str) -> str:
+    h = hashlib.sha256()
+    with open(path, "rb") as f:
+        for chunk in iter(lambda: f.read(65536), b""):
+            h.update(chunk)
+    return h.hexdigest()
+
+
+def parse_manifest(data: bytes) -> dict:
+    """Return path -> hash map from manifest bytes."""
+    try:
+        doc = json.loads(data.decode("utf-8"))
+    except (UnicodeDecodeError, json.JSONDecodeError, TypeError, ValueError):
+        return {}
+    if not isinstance(doc, dict):
+        return {}
+    files = doc.get("files")
+    return dict(files) if isinstance(files, dict) else {}
+
+
+def build_manifest_bytes(files: dict) -> bytes:
+    doc = {
+        "version": MANIFEST_VERSION,
+        "algorithm": HASH_ALGO,
+        "files": files,
+    }
+    return json.dumps(doc, separators=(",", ":")).encode("utf-8")

device.py

@@ -10,6 +10,14 @@ import os
 import time
 import serial
 
+from deploy_manifest import (
+    MANIFEST_FILENAME,
+    build_manifest_bytes,
+    normalize_remote_path,
+    parse_manifest,
+    sha256_hex_file,
+)
+
 # Add lib directory to path - handle both normal execution and PyInstaller bundle
 if getattr(sys, 'frozen', False):
     # Running as a PyInstaller bundle
@@ -109,13 +117,41 @@ class DeviceConnection:
         finally:
             self.disconnect()
 
-    def upload_directory(self, local_dir, remote_dir=None):
+    def _manifest_remote_path(self) -> str:
+        return "/" + MANIFEST_FILENAME
+
+    def read_hash_manifest(self) -> dict:
+        """Load path -> sha256 hex map from file_hashes.json on the device."""
+        remote = self._manifest_remote_path()
+        if not self.transport.fs_exists(remote):
+            return {}
+        try:
+            data = self.transport.fs_readfile(remote)
+            return parse_manifest(data)
+        except Exception:
+            return {}
+
+    def write_hash_manifest(self, files: dict) -> None:
+        """Write merged file_hashes.json to the device root."""
+        self._fs_writefile_with_wdt(
+            self._manifest_remote_path(),
+            build_manifest_bytes(files),
+        )
+    
+    def upload_directory(self, local_dir, remote_dir=None, *, force: bool = False):
         """
         Upload a directory recursively to the device.
         
+        Skips files whose sha256 matches file_hashes.json on the device unless
+        force is True. Updates the manifest after upload.
+        
         Args:
             local_dir: Local directory path to upload
             remote_dir: Remote directory path (default: root, uses basename of local_dir)
+            force: Upload every file even when the manifest hash matches
+        
+        Returns:
+            (files_copied, dirs_created, files_skipped)
         """
         import os
         
@@ -129,15 +165,19 @@ class DeviceConnection:
                 remote_dir = os.path.basename(os.path.abspath(local_dir))
             
             # Ensure remote directory exists
-            if not self.transport.fs_exists(remote_dir):
+            if remote_dir and not self.transport.fs_exists(remote_dir):
                 self.transport.fs_mkdir(remote_dir)
             
+            manifest = {} if force else self.read_hash_manifest()
+            
             # Walk through local directory and copy files
             files_copied = 0
+            files_skipped = 0
             dirs_created = 0
             
             for root, dirs, files in os.walk(local_dir):
-                # Calculate relative path from local_dir
+                # Never upload Python bytecode trees (MicroPython does not use them).
+                dirs[:] = [d for d in dirs if d != "__pycache__"]
                 rel_path = os.path.relpath(root, local_dir)
                 
                 # Build remote path
@@ -156,8 +196,12 @@ class DeviceConnection:
                     self.transport.fs_mkdir(remote_base)
                     dirs_created += 1
                 
-                # Copy files
+                # Copy files (skip bytecode; __pycache__ dirs are pruned above)
                 for file in files:
+                    if file.endswith((".pyc", ".pyo")):
+                        continue
+                    if file == MANIFEST_FILENAME:
+                        continue
                     local_file = os.path.join(root, file)
                     # Handle root directory case properly
                     if remote_base == '/':
@@ -165,13 +209,23 @@ class DeviceConnection:
                     else:
                         remote_file = '/'.join([remote_base, file])
                     
+                    manifest_key = normalize_remote_path(remote_file)
+                    local_hash = sha256_hex_file(local_file)
+                    if not force and manifest.get(manifest_key) == local_hash:
+                        print(f"Skipping (unchanged): {remote_file}", file=sys.stderr)
+                        files_skipped += 1
+                        continue
+                    
                     print(f"Uploading: {remote_file}", file=sys.stderr)
                     with open(local_file, 'rb') as f:
                         data = f.read()
                     self._fs_writefile_with_wdt(remote_file, data)
+                    manifest[manifest_key] = local_hash
                     files_copied += 1
             
-            return files_copied, dirs_created
+            self.write_hash_manifest(manifest)
+            
+            return files_copied, dirs_created, files_skipped
         finally:
             self.disconnect()
     

host_ports.py

@@ -0,0 +1,25 @@
+"""Host serial port list filtering for led-tool /ports API."""
+import re
+
+# Exclude /dev/ttyS2 and higher (keep ttyS0, ttyS1; keep ttyACM*, ttyUSB*, etc.)
+_TTYS_HIGH = re.compile(r"^/dev/ttyS([2-9]|[1-9]\d+)$")
+
+
+def include_host_serial_device(device: str) -> bool:
+    return not _TTYS_HIGH.match(device or "")
+
+
+def _is_na(value: str) -> bool:
+    return (value or "").strip().lower() in ("n/a", "na")
+
+
+def include_host_serial_port(port: dict) -> bool:
+    if not include_host_serial_device(port.get("device", "")):
+        return False
+    if _is_na(port.get("description")) or _is_na(port.get("hwid")):
+        return False
+    return True
+
+
+def filter_port_dicts(ports: list) -> list:
+    return [p for p in ports if include_host_serial_port(p)]

static/settings_editor.html

@@ -0,0 +1,210 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <meta charset="UTF-8" />
+  <title>LED device settings</title>
+  <meta name="viewport" content="width=device-width, initial-scale=1" />
+  <style>
+    :root {
+      color-scheme: dark;
+      --text: #e5e7eb;
+      --muted: #9ca3af;
+      --border: #374151;
+      --accent: #3b82f6;
+      --danger: #f87171;
+    }
+    * { box-sizing: border-box; }
+    body {
+      margin: 0;
+      font-family: system-ui, sans-serif;
+      background: #0b1020;
+      color: var(--text);
+      padding: 1rem;
+    }
+    h1 { font-size: 1.15rem; margin: 0 0 0.35rem; }
+    .muted { color: var(--muted); font-size: 0.9rem; margin-bottom: 1rem; }
+    .card {
+      border: 1px solid var(--border);
+      border-radius: 8px;
+      padding: 1rem;
+      margin-bottom: 1rem;
+      background: #111827;
+    }
+    label { display: block; font-size: 0.85rem; margin-bottom: 0.25rem; color: var(--muted); }
+    input, select, textarea {
+      width: 100%;
+      padding: 0.5rem;
+      border-radius: 4px;
+      border: 1px solid var(--border);
+      background: #1f2937;
+      color: var(--text);
+      margin-bottom: 0.65rem;
+    }
+    .row { display: flex; gap: 0.5rem; flex-wrap: wrap; align-items: flex-end; }
+    .row > * { flex: 1; min-width: 10rem; }
+    .btn {
+      padding: 0.45rem 0.85rem;
+      border: none;
+      border-radius: 4px;
+      cursor: pointer;
+      background: #4b5563;
+      color: #fff;
+      font-size: 0.9rem;
+    }
+    .btn-primary { background: var(--accent); }
+    .btn:disabled { opacity: 0.5; cursor: not-allowed; }
+    .grid {
+      display: grid;
+      grid-template-columns: repeat(auto-fill, minmax(11rem, 1fr));
+      gap: 0 0.5rem;
+    }
+    #status { font-size: 0.85rem; margin-top: 0.5rem; }
+    #status.error { color: var(--danger); }
+    .flash {
+      display: none;
+      padding: 0.5rem 0.75rem;
+      border-radius: 4px;
+      margin-bottom: 0.75rem;
+      background: #14532d;
+      color: #86efac;
+    }
+    .flash.error { background: #5e1b1b; color: #fca5a5; }
+    .flash.show { display: block; }
+    [hidden] { display: none !important; }
+  </style>
+</head>
+<body data-api-base="/led-tool">
+  <h1>Device settings (USB)</h1>
+    <p class="muted">Edit <code>settings.json</code> via <strong>Web Serial</strong> (USB on this computer) or <strong>host serial</strong> (Pi running <code>led-cli</code>). Use <strong>Connect</strong> for your transport, then <strong>Download</strong> or <strong>Upload</strong>.</p>
+  <div id="flash" class="flash"></div>
+
+  <div class="card" id="webserial-wrap" hidden>
+    <h2 style="font-size:1rem;margin:0 0 0.5rem;">Web Serial</h2>
+    <div class="row">
+      <button type="button" class="btn btn-primary" id="webserial-connect">Connect USB</button>
+      <button type="button" class="btn" id="webserial-disconnect" hidden>Disconnect</button>
+    </div>
+  </div>
+
+  <div class="card" id="host-serial-wrap">
+    <h2 style="font-size:1rem;margin:0 0 0.5rem;">Host serial</h2>
+    <label for="host-port">Port</label>
+    <select id="host-port"><option value="">Select port</option></select>
+    <div class="row">
+      <button type="button" class="btn btn-primary" id="host-connect">Connect</button>
+      <button type="button" class="btn" id="host-disconnect" hidden>Disconnect</button>
+      <button type="button" class="btn" id="btn-refresh-ports">Refresh ports</button>
+    </div>
+  </div>
+
+  <div class="card">
+    <div class="row" style="margin-bottom:0.75rem;">
+      <button type="button" class="btn btn-primary" id="btn-download">Download</button>
+      <button type="button" class="btn btn-primary" id="btn-upload">Upload &amp; reset</button>
+      <button type="button" class="btn" id="btn-from-json">JSON → form</button>
+      <button type="button" class="btn" id="btn-to-json">Form → JSON</button>
+    </div>
+    <p id="status">Ready</p>
+
+    <div class="grid">
+      <div>
+        <label for="name">Name</label>
+        <input id="name" data-setting="name" type="text" />
+      </div>
+      <div>
+        <label for="num_leds">Num LEDs</label>
+        <input id="num_leds" data-setting="num_leds" type="number" min="1" />
+      </div>
+      <div>
+        <label for="led_pin">LED pin</label>
+        <input id="led_pin" data-setting="led_pin" type="number" min="0" />
+      </div>
+      <div>
+        <label for="brightness">Brightness</label>
+        <input id="brightness" data-setting="brightness" type="number" min="0" max="255" />
+      </div>
+      <div>
+        <label for="color_order">Colour order</label>
+        <select id="color_order" data-setting="color_order">
+          <option value=""></option>
+          <option value="rgb">rgb</option>
+          <option value="rbg">rbg</option>
+          <option value="grb">grb</option>
+          <option value="gbr">gbr</option>
+          <option value="brg">brg</option>
+          <option value="bgr">bgr</option>
+        </select>
+      </div>
+      <div>
+        <label for="transport_type">Transport</label>
+        <select id="transport_type" data-setting="transport_type">
+          <option value=""></option>
+          <option value="espnow">espnow</option>
+          <option value="wifi">wifi</option>
+        </select>
+      </div>
+      <div>
+        <label for="ssid">WiFi SSID</label>
+        <input id="ssid" data-setting="ssid" type="text" />
+      </div>
+      <div>
+        <label for="password">WiFi password</label>
+        <input id="password" data-setting="password" type="password" />
+      </div>
+      <div>
+        <label for="wifi_channel">WiFi channel</label>
+        <input id="wifi_channel" data-setting="wifi_channel" type="number" min="1" max="11" />
+      </div>
+      <div>
+        <label for="default">Default preset</label>
+        <input id="default" data-setting="default" type="text" />
+      </div>
+      <div>
+        <label for="id">Device id (ESP-NOW)</label>
+        <input id="id" data-setting="id" type="number" min="0" max="255" />
+      </div>
+      <div>
+        <label for="debug">Debug</label>
+        <select id="debug" data-setting="debug">
+          <option value=""></option>
+          <option value="False">False</option>
+          <option value="True">True</option>
+        </select>
+      </div>
+    </div>
+  </div>
+
+  <div class="card">
+    <label for="raw_json">Raw settings.json</label>
+    <textarea id="raw_json" rows="14" spellcheck="false">{}</textarea>
+  </div>
+
+  <script>
+    (function () {
+      const api =
+        document.body.getAttribute('data-api-base') ??
+        (location.pathname.includes('/led-tool') ? '/led-tool' : '');
+      const prefix = api + '/static';
+      const v = '20260520';
+      function loadScript(url) {
+        return new Promise((resolve, reject) => {
+          const s = document.createElement('script');
+          s.src = url + (url.includes('?') ? '&' : '?') + 'v=' + v;
+          s.onload = () => resolve();
+          s.onerror = () => reject(new Error('Failed to load ' + url));
+          document.body.appendChild(s);
+        });
+      }
+      loadScript(prefix + '/web_serial.js')
+        .then(() => loadScript(prefix + '/settings_editor.js'))
+        .catch((e) => {
+          const el = document.getElementById('flash');
+          if (el) {
+            el.textContent = e.message;
+            el.className = 'flash error show';
+          }
+        });
+    })();
+  </script>
+</body>
+</html>

static/settings_editor.js

@@ -0,0 +1,421 @@
+(function () {
+  const LOG = '[led-tool/editor]';
+  const log = (...args) => console.log(LOG, ...args);
+
+  const apiBase =
+    (document.body && document.body.dataset.apiBase) ||
+    (window.location.pathname.includes('/led-tool') ? '/led-tool' : '');
+  const statusEl = document.getElementById('status');
+  const messageEl = document.getElementById('flash');
+  const portSelect = document.getElementById('host-port');
+  const rawJson = document.getElementById('raw_json');
+  const hostWrap = document.getElementById('host-serial-wrap');
+  const webWrap = document.getElementById('webserial-wrap');
+  const connectBtn = document.getElementById('webserial-connect');
+  const disconnectBtn = document.getElementById('webserial-disconnect');
+  const hostConnectBtn = document.getElementById('host-connect');
+  const hostDisconnectBtn = document.getElementById('host-disconnect');
+  const refreshPortsBtn = document.getElementById('btn-refresh-ports');
+
+  const DEFAULT_HOST_PORT = '/dev/ttyACM0';
+
+  let webClient = null;
+  let webPort = null;
+  let hostConnected = false;
+  let hostConnectedPort = '';
+  let transferBusy = false;
+  let webConnectBusy = false;
+
+  const webSerialOk = window.LedToolWebSerial && window.LedToolWebSerial.supported();
+  let webSerialGrantedCount = 0;
+
+  function setStatus(text, isError) {
+    if (!statusEl) return;
+    statusEl.textContent = text;
+    statusEl.classList.toggle('error', Boolean(isError));
+  }
+
+  function flash(text, isError) {
+    if (!messageEl) return;
+    messageEl.textContent = text;
+    messageEl.className = isError ? 'flash error show' : 'flash show';
+    setTimeout(() => messageEl.classList.remove('show'), 5000);
+  }
+
+  function errorMessage(e) {
+    if (!e) return 'Unknown error';
+    if (typeof e === 'string') return e;
+    return e.message || String(e);
+  }
+
+  function onWebSerialTransferError(e) {
+    if (webClient) webClient.inRawRepl = false;
+    return errorMessage(e);
+  }
+
+  function formToObject() {
+    const out = {};
+    document.querySelectorAll('[data-setting]').forEach((el) => {
+      const key = el.getAttribute('data-setting');
+      if (!key) return;
+      const raw = (el.value || '').trim();
+      if (raw === '') return;
+      if (el.type === 'number') {
+        const n = parseInt(raw, 10);
+        if (!Number.isNaN(n)) out[key] = n;
+      } else if (el.tagName === 'SELECT' && el.id === 'debug') {
+        out[key] = raw === 'True';
+      } else {
+        out[key] = raw;
+      }
+    });
+    return out;
+  }
+
+  function objectToForm(settings) {
+    if (!settings || typeof settings !== 'object') return;
+    document.querySelectorAll('[data-setting]').forEach((el) => {
+      const key = el.getAttribute('data-setting');
+      if (!key || !Object.prototype.hasOwnProperty.call(settings, key)) return;
+      const v = settings[key];
+      if (el.id === 'debug') {
+        el.value = v === true || v === 'True' ? 'True' : 'False';
+      } else {
+        el.value = v === undefined || v === null ? '' : String(v);
+      }
+    });
+    if (rawJson) rawJson.value = JSON.stringify(settings, null, 2);
+  }
+
+  function usingWebSerial() {
+    return webClient && webClient.connected;
+  }
+
+  function usingHostSerial() {
+    return hostConnected && Boolean(hostConnectedPort);
+  }
+
+  function updateUi() {
+    const webOpen = usingWebSerial();
+    const hostOpen = usingHostSerial();
+    if (webWrap) webWrap.hidden = !webSerialOk || hostOpen;
+    if (connectBtn) connectBtn.hidden = webOpen || hostOpen || !webSerialOk;
+    if (disconnectBtn) disconnectBtn.hidden = !webOpen;
+    if (hostWrap) hostWrap.hidden = webOpen;
+    const hostFieldsLocked = webOpen || hostOpen;
+    if (portSelect) portSelect.disabled = hostFieldsLocked;
+    if (refreshPortsBtn) refreshPortsBtn.disabled = hostFieldsLocked;
+    if (hostConnectBtn) hostConnectBtn.hidden = hostOpen || webOpen;
+    if (hostDisconnectBtn) hostDisconnectBtn.hidden = !hostOpen || webOpen;
+    if (webOpen) {
+      setStatus('USB open (device not reset until Download/Upload).');
+    } else if (hostOpen) {
+      setStatus(`Host serial: ${hostConnectedPort} (use Download or Upload).`);
+    } else if (webSerialOk) {
+      if (webSerialGrantedCount === 1) {
+        setStatus('Connect USB (one remembered port) or host serial, then Download or Upload.');
+      } else {
+        setStatus('Connect host serial or Web Serial USB, then Download or Upload.');
+      }
+    } else {
+      setStatus(`Connect host serial (default ${DEFAULT_HOST_PORT}).`);
+    }
+  }
+
+  async function loadHostPorts() {
+    if (!portSelect) return;
+    try {
+      const res = await fetch(`${apiBase}/ports`);
+      const data = await res.json();
+      const prev = portSelect.value;
+      portSelect.innerHTML = '<option value="">Select port</option>';
+      for (const p of data.ports || []) {
+        const opt = document.createElement('option');
+        opt.value = p.device;
+        opt.textContent = `${p.device} - ${p.description || 'device'}`;
+        portSelect.appendChild(opt);
+      }
+      const acm0 = DEFAULT_HOST_PORT;
+      const hasAcm0 = [...portSelect.options].some((o) => o.value === acm0);
+      if (hasAcm0) {
+        portSelect.value = acm0;
+      } else if (prev && [...portSelect.options].some((o) => o.value === prev)) {
+        portSelect.value = prev;
+      }
+    } catch (e) {
+      flash(`Could not list host ports: ${e.message}`, true);
+    }
+  }
+
+  function selectedHostPort() {
+    return portSelect && portSelect.value ? portSelect.value.trim() : '';
+  }
+
+  function hostPort() {
+    if (hostConnected && hostConnectedPort) return hostConnectedPort;
+    return selectedHostPort();
+  }
+
+  function connectHostSerial() {
+    if (usingWebSerial()) {
+      disconnectWebSerial();
+    }
+    const port = selectedHostPort();
+    if (!port) {
+      flash('Select a host serial port.', true);
+      return;
+    }
+    hostConnectedPort = port;
+    hostConnected = true;
+    log('connectHostSerial', port);
+    updateUi();
+    flash(`Host serial ready: ${port}`, false);
+  }
+
+  function disconnectHostSerial() {
+    hostConnected = false;
+    hostConnectedPort = '';
+    updateUi();
+  }
+
+  async function downloadHost() {
+    const port = hostConnectedPort || hostPort();
+    if (!port) {
+      flash('Connect host serial first.', true);
+      return;
+    }
+    log('downloadHost', port);
+    setStatus('Downloading from device (host serial)...');
+    const res = await fetch(`${apiBase}/settings?port=${encodeURIComponent(port)}`);
+    const data = await res.json();
+    log('downloadHost response', { ok: res.ok, status: res.status, data });
+    if (!res.ok) {
+      throw new Error(data.error || 'Download failed');
+    }
+    if (!data.settings) {
+      throw new Error('No settings in response (check CLI output)');
+    }
+    objectToForm(data.settings);
+    flash('Settings downloaded.', false);
+    setStatus(`Downloaded from ${port}`);
+  }
+
+  async function uploadHost() {
+    const port = hostConnectedPort || hostPort();
+    if (!port) {
+      flash('Connect host serial first.', true);
+      return;
+    }
+    const payload = { port, ...formToObject() };
+    log('uploadHost', payload);
+    setStatus('Uploading via host serial (led-cli)...');
+    const res = await fetch(`${apiBase}/settings`, {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify(payload),
+    });
+    const data = await res.json();
+    if (!res.ok) throw new Error(data.error || 'Upload failed');
+    if (!data.ok) throw new Error(data.stderr || 'led-cli failed');
+    flash('Settings uploaded; device resetting.', false);
+    setStatus('Upload complete.');
+  }
+
+  async function connectWebSerial() {
+    if (webConnectBusy) return;
+    if (!window.LedToolWebSerial || !window.LedToolWebSerial.supported()) {
+      flash('Web Serial not supported (use Chrome or Edge over HTTPS or localhost).', true);
+      return;
+    }
+    if (usingWebSerial()) {
+      flash('USB already connected.', false);
+      return;
+    }
+    if (usingHostSerial()) {
+      disconnectHostSerial();
+    }
+    webConnectBusy = true;
+    try {
+      log('connectWebSerial: requestPort');
+      setStatus('Opening USB port…');
+      webPort = await window.LedToolWebSerial.requestPort();
+      log('connectWebSerial: port selected', webPort);
+      webClient = new window.LedToolWebSerial.MicroPythonRawRepl();
+      await webClient.connect(webPort);
+      updateUi();
+      flash('USB port open. Wait for boot, then Download.', false);
+    } finally {
+      webConnectBusy = false;
+    }
+  }
+
+  async function disconnectWebSerial() {
+    if (webClient) {
+      try {
+        await webClient.disconnect();
+      } catch (_) {
+        /* ignore */
+      }
+    }
+    webClient = null;
+    webPort = null;
+    updateUi();
+  }
+
+  async function downloadWebSerial() {
+    log('downloadWebSerial');
+    setStatus('Reading settings from device (Web Serial)…');
+    const settings = await webClient.readSettingsJson();
+    log('downloadWebSerial result', settings);
+    objectToForm(settings);
+    if (rawJson) rawJson.value = JSON.stringify(settings, null, 2);
+    flash('Settings read over Web Serial.', false);
+    setStatus('Downloaded via Web Serial.');
+  }
+
+  async function uploadWebSerial() {
+    log('uploadWebSerial');
+    let settings = {};
+    if (rawJson && rawJson.value.trim()) {
+      try {
+        settings = JSON.parse(rawJson.value);
+      } catch (e) {
+        flash('Invalid JSON in raw panel.', true);
+        return;
+      }
+    } else {
+      settings = await webClient.readSettingsJson();
+      Object.assign(settings, formToObject());
+    }
+    await webClient.writeSettingsJson(settings);
+    flash('Uploaded via Web Serial; device resetting.', false);
+    setStatus('Upload complete.');
+    await disconnectWebSerial();
+  }
+
+  document.getElementById('btn-download')?.addEventListener('click', async () => {
+    if (transferBusy) return;
+    transferBusy = true;
+    try {
+      if (usingWebSerial()) {
+        await downloadWebSerial();
+      } else if (usingHostSerial()) {
+        await downloadHost();
+      } else {
+        flash(
+          webSerialOk
+            ? 'Connect host serial or Web Serial USB first.'
+            : 'Click Connect on host serial first.',
+          true,
+        );
+      }
+    } catch (e) {
+      console.error(LOG, 'download failed', e);
+      const msg = usingWebSerial() ? onWebSerialTransferError(e) : errorMessage(e);
+      if (rawJson) rawJson.value = msg;
+      flash(msg, true);
+      setStatus(msg, true);
+    } finally {
+      transferBusy = false;
+    }
+  });
+
+  document.getElementById('btn-upload')?.addEventListener('click', async () => {
+    if (transferBusy) return;
+    transferBusy = true;
+    try {
+      if (usingWebSerial()) {
+        await uploadWebSerial();
+      } else if (usingHostSerial()) {
+        await uploadHost();
+      } else {
+        flash(
+          webSerialOk
+            ? 'Connect host serial or Web Serial USB first.'
+            : 'Click Connect on host serial first.',
+          true,
+        );
+      }
+    } catch (e) {
+      console.error(LOG, 'upload failed', e);
+      const msg = usingWebSerial() ? onWebSerialTransferError(e) : errorMessage(e);
+      flash(msg, true);
+      setStatus(msg, true);
+    } finally {
+      transferBusy = false;
+    }
+  });
+
+  document.getElementById('btn-from-json')?.addEventListener('click', () => {
+    try {
+      const parsed = JSON.parse(rawJson.value || '{}');
+      objectToForm(parsed);
+      flash('Form updated from JSON.', false);
+    } catch (e) {
+      flash('Invalid JSON.', true);
+    }
+  });
+
+  document.getElementById('btn-to-json')?.addEventListener('click', () => {
+    const merged = formToObject();
+    if (rawJson && rawJson.value.trim()) {
+      try {
+        Object.assign(merged, JSON.parse(rawJson.value));
+      } catch (_) {
+        /* use form only */
+      }
+    }
+    rawJson.value = JSON.stringify(merged, null, 2);
+    flash('JSON updated from form.', false);
+  });
+
+  connectBtn?.addEventListener('click', () => {
+    connectWebSerial().catch((e) => {
+      disconnectWebSerial();
+      const msg =
+        e.name === 'NotFoundError'
+          ? 'No USB device selected.'
+          : e.name === 'SecurityError'
+            ? 'Web Serial blocked (open LED Tool in a top-level tab, or use host serial on the Pi).'
+            : e.message || String(e);
+      flash(msg, true);
+      setStatus(msg, true);
+    });
+  });
+
+  disconnectBtn?.addEventListener('click', () => {
+    disconnectWebSerial();
+    flash('Web Serial disconnected.', false);
+  });
+
+  refreshPortsBtn?.addEventListener('click', () => loadHostPorts());
+
+  hostConnectBtn?.addEventListener('click', () => connectHostSerial());
+
+  hostDisconnectBtn?.addEventListener('click', () => {
+    disconnectHostSerial();
+    flash('Host serial disconnected.', false);
+  });
+
+  window.addEventListener('beforeunload', () => {
+    if (webClient) {
+      webClient.disconnect();
+    }
+  });
+
+  async function refreshWebSerialGrantHint() {
+    if (!webSerialOk || !window.LedToolWebSerial.getGrantedPorts) return;
+    try {
+      const ports = await window.LedToolWebSerial.getGrantedPorts();
+      webSerialGrantedCount = ports.length;
+      updateUi();
+    } catch (_) {
+      /* ignore */
+    }
+  }
+
+  log('settings editor ready', { apiBase, webSerialOk });
+  updateUi();
+  loadHostPorts();
+  refreshWebSerialGrantHint();
+})();

static/web_serial.js

@@ -0,0 +1,653 @@
+/**
+ * MicroPython raw REPL over Web Serial (mpremote-compatible).
+ */
+(function (global) {
+  const RAW_REPL_BANNER = 'raw REPL; CTRL-B to exit\r\n';
+  const SOFT_REBOOT_MARKERS = ['soft reboot\r\n', 'MPY: soft reboot\r\n'];
+  const LOG = '[led-tool/serial]';
+
+  function log(...args) {
+    console.log(LOG, ...args);
+  }
+
+  function logDebug(...args) {
+    console.debug(LOG, ...args);
+  }
+
+  function describeBytes(data) {
+    if (!data || !data.length) return '(empty)';
+    const u8 = data instanceof Uint8Array ? data : new Uint8Array(data);
+    if (u8.length <= 64) {
+      return Array.from(u8)
+        .map((b) => (b >= 0x20 && b < 0x7f ? String.fromCharCode(b) : `\\x${b.toString(16).padStart(2, '0')}`))
+        .join('');
+    }
+    return `${u8.length} bytes: ${decodeText(u8.slice(0, 80))}…`;
+  }
+
+  function sleep(ms) {
+    return new Promise((resolve) => setTimeout(resolve, ms));
+  }
+
+  /** Common ESP32 USB-UART bridges (usbVendorId only per Web Serial API). */
+  const ESP32_USB_FILTERS = [
+    { usbVendorId: 0x303a }, /* Espressif */
+    { usbVendorId: 0x10c4 }, /* Silicon Labs CP210x */
+    { usbVendorId: 0x1a86 }, /* WCH CH340 */
+    { usbVendorId: 0x0403 }, /* FTDI */
+  ];
+
+  async function deassertDtrRts(port) {
+    if (!port || !port.setSignals) return;
+    try {
+      await port.setSignals({ dataTerminalReady: false, requestToSend: false });
+    } catch (_) {
+      /* ignore — some adapters/browsers reject setSignals */
+    }
+  }
+
+  function bytesIndexOf(buf, suffix) {
+    if (!suffix.length) return 0;
+    if (buf.length < suffix.length) return -1;
+    for (let i = 0; i <= buf.length - suffix.length; i += 1) {
+      let ok = true;
+      for (let j = 0; j < suffix.length; j += 1) {
+        if (buf[i + j] !== suffix[j]) {
+          ok = false;
+          break;
+        }
+      }
+      if (ok) return i;
+    }
+    return -1;
+  }
+
+  function bufferEndsWithFriendlyRepl(buf) {
+    if (bufferLooksLikeEspRomBoot(buf) && !bufferHasMicroPython(buf)) return false;
+    const tail = decodeText(Uint8Array.from(buf.slice(-80)));
+    return /(?:\r\n|\n)>>> ?$/.test(tail);
+  }
+
+  function bufferLooksLikeEspRomBoot(buf) {
+    if (bufferIndicatesRuntime(buf)) return false;
+    const text = decodeText(Uint8Array.from(buf.slice(-512)));
+    return /SPI_FAST_FLASH_BOOT|rst:0x/.test(text) && !/entry 0x403/.test(text);
+  }
+
+  /** MicroPython is up (banner, REPL, raw REPL, or post-ROM heap lines from boot). */
+  function bufferIndicatesRuntime(buf) {
+    const text = decodeText(Uint8Array.from(buf));
+    if (text.includes('MicroPython')) return true;
+    if (text.includes('raw REPL; CTRL-B to exit')) return true;
+    if (/(?:\r\n|\n)>>> ?/.test(text)) return true;
+    if (text.includes('entry 0x') && (/['"]?free['"]?\s*:/.test(text) || /,\s*'free'/.test(text))) {
+      return true;
+    }
+    return false;
+  }
+
+  function bufferHasMicroPython(buf) {
+    return bufferIndicatesRuntime(buf);
+  }
+
+  function decodeText(u8) {
+    return new TextDecoder('utf-8', { fatal: false }).decode(u8);
+  }
+
+  function extractJsonObject(text) {
+    const t = (text || '').trim();
+    const start = t.indexOf('{');
+    const end = t.lastIndexOf('}');
+    if (start === -1 || end === -1 || end < start) {
+      throw new Error(`No JSON object in device output: ${t.slice(0, 400)}`);
+    }
+    return JSON.parse(t.slice(start, end + 1));
+  }
+
+  class MicroPythonRawRepl {
+    constructor() {
+      this.port = null;
+      this.reader = null;
+      this.writer = null;
+      this.portOpen = false;
+      this.inRawRepl = false;
+      this._rxBuf = [];
+      this.useRawPaste = true;
+      this._replLock = null;
+    }
+
+    get connected() {
+      return Boolean(this.portOpen && this.writer);
+    }
+
+    _appendRx(chunk) {
+      if (!chunk || !chunk.length) return;
+      logDebug('rx chunk', chunk.length, describeBytes(chunk));
+      for (let i = 0; i < chunk.length; i += 1) this._rxBuf.push(chunk[i]);
+    }
+
+    async _readStreamChunk(timeoutMs) {
+      if (!this.reader) return null;
+      const result = await Promise.race([
+        this.reader.read(),
+        sleep(timeoutMs).then(() => ({ timedOut: true })),
+      ]);
+      if (result.timedOut) return null;
+      if (result.done) return null;
+      return result.value || null;
+    }
+
+    /** Match suffix anywhere in the buffer; keep bytes after the match for the next read. */
+    async readUntil(suffixBytes, timeoutMs = 15000) {
+      const deadline = Date.now() + timeoutMs;
+      while (Date.now() < deadline) {
+        const idx = bytesIndexOf(this._rxBuf, suffixBytes);
+        if (idx >= 0) {
+          const end = idx + suffixBytes.length;
+          const matched = Uint8Array.from(this._rxBuf.slice(0, end));
+          this._rxBuf.splice(0, end);
+          logDebug('readUntil matched', JSON.stringify(decodeText(suffixBytes)), 'len', matched.length);
+          return matched;
+        }
+        const chunk = await this._readStreamChunk(Math.min(300, Math.max(1, deadline - Date.now())));
+        if (chunk && chunk.length) {
+          this._appendRx(chunk);
+        } else {
+          await sleep(5);
+        }
+      }
+      const tail = decodeText(Uint8Array.from(this._rxBuf.slice(-240)));
+      const err = `Timed out waiting for ${JSON.stringify(decodeText(suffixBytes))} (tail: ${JSON.stringify(tail)})`;
+      log('readUntil timeout', err);
+      throw new Error(err);
+    }
+
+    async readUntilAny(suffixList, timeoutMs = 15000) {
+      const deadline = Date.now() + timeoutMs;
+      while (Date.now() < deadline) {
+        for (const suffixBytes of suffixList) {
+          const idx = bytesIndexOf(this._rxBuf, suffixBytes);
+          if (idx >= 0) {
+            const end = idx + suffixBytes.length;
+            const matched = Uint8Array.from(this._rxBuf.slice(0, end));
+            this._rxBuf.splice(0, end);
+            logDebug('readUntilAny matched', JSON.stringify(decodeText(suffixBytes)));
+            return matched;
+          }
+        }
+        const chunk = await this._readStreamChunk(Math.min(300, Math.max(1, deadline - Date.now())));
+        if (chunk && chunk.length) this._appendRx(chunk);
+        else await sleep(5);
+      }
+      const tail = decodeText(Uint8Array.from(this._rxBuf.slice(-240)));
+      throw new Error(
+        `Timed out waiting for one of ${suffixList.map((s) => JSON.stringify(decodeText(s))).join(', ')} (tail: ${JSON.stringify(tail)})`,
+      );
+    }
+
+    async readExact(n, timeoutMs = 10000) {
+      const deadline = Date.now() + timeoutMs;
+      while (this._rxBuf.length < n && Date.now() < deadline) {
+        const chunk = await this._readStreamChunk(Math.min(300, Math.max(1, deadline - Date.now())));
+        if (chunk && chunk.length) this._appendRx(chunk);
+        else await sleep(5);
+      }
+      if (this._rxBuf.length < n) {
+        throw new Error(`Expected ${n} bytes, got ${this._rxBuf.length}`);
+      }
+      return Uint8Array.from(this._rxBuf.splice(0, n));
+    }
+
+    async connect(serialPort) {
+      log('connect: opening port');
+      await this.disconnect();
+      this.port = serialPort;
+      this._rxBuf = [];
+      await this.port.open({
+        baudRate: 115200,
+        dataBits: 8,
+        stopBits: 1,
+        parity: 'none',
+        flowControl: 'none',
+        bufferSize: 65536,
+      });
+      await deassertDtrRts(this.port);
+      await sleep(50);
+      await deassertDtrRts(this.port);
+      this.reader = this.port.readable.getReader();
+      this.writer = this.port.writable.getWriter();
+      this.portOpen = true;
+      await sleep(100);
+      await this.collectIncoming(8000);
+      if (bufferIndicatesRuntime(this._rxBuf)) {
+        log('connect: MicroPython output seen during open');
+      }
+      log('connect: port open (raw REPL not entered yet)');
+    }
+
+    /** Read serial into _rxBuf without discarding (for post-open boot). */
+    async collectIncoming(maxMs) {
+      const deadline = Date.now() + maxMs;
+      while (Date.now() < deadline) {
+        const chunk = await this._readStreamChunk(Math.min(80, Math.max(1, deadline - Date.now())));
+        if (chunk && chunk.length) this._appendRx(chunk);
+        else if (
+          bufferHasMicroPython(this._rxBuf) ||
+          bufferEndsWithFriendlyRepl(this._rxBuf) ||
+          bytesIndexOf(this._rxBuf, new TextEncoder().encode(RAW_REPL_BANNER)) >= 0
+        ) {
+          break;
+        } else {
+          await sleep(15);
+        }
+      }
+    }
+
+    async ensureRawRepl() {
+      if (this.inRawRepl) return;
+      if (this._replLock) {
+        await this._replLock;
+        return;
+      }
+      log('ensureRawRepl: entering raw REPL');
+      // USB open already resets the ESP32; skip soft-reset (unlike host led-cli/mpremote).
+      this._replLock = this.enterRawRepl(false).finally(() => {
+        this._replLock = null;
+      });
+      await this._replLock;
+    }
+
+    async disconnect() {
+      log('disconnect');
+      this._replLock = null;
+      const wasRaw = this.inRawRepl;
+      this.inRawRepl = false;
+      this.portOpen = false;
+      this.useRawPaste = true;
+      if (this.writer && wasRaw) {
+        try {
+          await this.writer.write(new Uint8Array([0x0d, 0x02]));
+        } catch (_) {
+          /* ignore */
+        }
+      }
+      if (this.reader) {
+        try {
+          await this.reader.cancel();
+          this.reader.releaseLock();
+        } catch (_) {
+          /* ignore */
+        }
+        this.reader = null;
+      }
+      if (this.writer) {
+        try {
+          await this.writer.close();
+          this.writer.releaseLock();
+        } catch (_) {
+          /* ignore */
+        }
+        this.writer = null;
+      }
+      if (this.port) {
+        try {
+          await deassertDtrRts(this.port);
+        } catch (_) {
+          /* ignore */
+        }
+        try {
+          await this.port.close();
+        } catch (_) {
+          /* ignore */
+        }
+        this.port = null;
+      }
+      this._rxBuf = [];
+    }
+
+    async writeBytes(data) {
+      if (!this.writer) throw new Error('Serial not connected');
+      logDebug('tx', describeBytes(data));
+      await this.writer.write(data);
+    }
+
+    async drainInput(maxMs = 400, clearBuffer = true) {
+      const deadline = Date.now() + maxMs;
+      while (Date.now() < deadline) {
+        const chunk = await this._readStreamChunk(40);
+        if (!chunk || !chunk.length) break;
+        if (!clearBuffer && chunk.length) this._appendRx(chunk);
+      }
+      if (clearBuffer) this._rxBuf.length = 0;
+    }
+
+    async sendCtrlA() {
+      await this.writeBytes(new Uint8Array([0x0d, 0x01]));
+    }
+
+    /** USB open often resets the ESP32; wait through ROM boot until MicroPython is up. */
+    async waitForMicroPythonBoot(timeoutMs = 60000) {
+      log('enterRawRepl: wait for MicroPython after boot', 'buf', this._rxBuf.length);
+      if (bufferHasMicroPython(this._rxBuf) || bufferEndsWithFriendlyRepl(this._rxBuf)) {
+        log('enterRawRepl: MicroPython already in buffer');
+        return;
+      }
+      const deadline = Date.now() + timeoutMs;
+      let nudgeSent = false;
+      let lastLog = Date.now();
+      while (Date.now() < deadline) {
+        if (bufferHasMicroPython(this._rxBuf) || bufferEndsWithFriendlyRepl(this._rxBuf)) {
+          log('enterRawRepl: MicroPython running');
+          return;
+        }
+        const text = decodeText(Uint8Array.from(this._rxBuf));
+        if (!nudgeSent && text.includes('entry 0x')) {
+          nudgeSent = true;
+          log('enterRawRepl: past ROM loader, nudge REPL');
+          await this.writeBytes(new Uint8Array([0x0d]));
+          await sleep(200);
+        }
+        if (Date.now() - lastLog > 5000) {
+          lastLog = Date.now();
+          log('enterRawRepl: still waiting…', 'buf', this._rxBuf.length);
+        }
+        const rem = Math.max(1, deadline - Date.now());
+        const chunk = await this._readStreamChunk(Math.min(300, rem));
+        if (chunk && chunk.length) this._appendRx(chunk);
+        else await sleep(bufferLooksLikeEspRomBoot(this._rxBuf) ? 20 : 10);
+      }
+      const tail = decodeText(Uint8Array.from(this._rxBuf.slice(-240)));
+      throw new Error(`Timed out waiting for MicroPython boot (tail: ${JSON.stringify(tail)})`);
+    }
+
+    /** Wait until raw REPL banner and `>` prompt (not banner alone — device may still be booting). */
+    async waitRawReplAfterSoftReboot(bannerBytes, bannerPromptBytes, timeoutMs = 15000) {
+      const deadline = Date.now() + timeoutMs;
+      while (Date.now() < deadline) {
+        const rem = Math.max(1, deadline - Date.now());
+        const promptAt = bytesIndexOf(this._rxBuf, bannerPromptBytes);
+        if (promptAt >= 0) {
+          this._rxBuf.splice(0, promptAt + bannerPromptBytes.length);
+          log('enterRawRepl: raw REPL prompt ready');
+          return;
+        }
+        if (bufferEndsWithFriendlyRepl(this._rxBuf)) {
+          log('enterRawRepl: friendly REPL, ctrl-A');
+          await this.sendCtrlA();
+          await sleep(30);
+          continue;
+        }
+        if (bufferLooksLikeEspRomBoot(this._rxBuf) && !bufferHasMicroPython(this._rxBuf)) {
+          logDebug('enterRawRepl: ROM boot in progress…');
+        }
+        const chunk = await this._readStreamChunk(Math.min(300, rem));
+        if (chunk && chunk.length) this._appendRx(chunk);
+        else await sleep(10);
+      }
+      const tail = decodeText(Uint8Array.from(this._rxBuf.slice(-240)));
+      throw new Error(
+        `Timed out waiting for raw REPL after soft reboot (tail: ${JSON.stringify(tail)})`,
+      );
+    }
+
+    /** Match mpremote SerialTransport.enter_raw_repl(soft_reset). */
+    async enterRawRepl(softReset = true) {
+      log('enterRawRepl', { softReset });
+      const bannerBytes = new TextEncoder().encode(RAW_REPL_BANNER);
+      const bannerPromptBytes = new TextEncoder().encode(RAW_REPL_BANNER + '>');
+      const softRebootBytes = SOFT_REBOOT_MARKERS.map((m) => new TextEncoder().encode(m));
+
+      if (
+        !bufferHasMicroPython(this._rxBuf) &&
+        !bufferEndsWithFriendlyRepl(this._rxBuf) &&
+        bytesIndexOf(this._rxBuf, bannerBytes) < 0
+      ) {
+        await this.waitForMicroPythonBoot(60000);
+      } else {
+        log('enterRawRepl: already have REPL output in buffer');
+      }
+
+      if (bufferEndsWithFriendlyRepl(this._rxBuf)) {
+        await this.writeBytes(new Uint8Array([0x0d, 0x03]));
+        await sleep(50);
+      }
+
+      let ctrlARetries = 0;
+      const maxCtrlARetries = 3;
+      while (ctrlARetries <= maxCtrlARetries) {
+        try {
+          await this.sendCtrlA();
+          await this.waitRawReplAfterSoftReboot(bannerBytes, bannerPromptBytes, 20000);
+          break;
+        } catch (e) {
+          if (ctrlARetries >= maxCtrlARetries) throw e;
+          ctrlARetries += 1;
+          log('enterRawRepl: retry ctrl-A', ctrlARetries, e.message);
+          this._rxBuf.length = 0;
+        }
+      }
+
+      if (softReset) {
+        log('enterRawRepl: soft reset');
+        await this.writeBytes(new Uint8Array([0x04]));
+        try {
+          await this.readUntilAny(softRebootBytes, 20000);
+          log('enterRawRepl: saw soft reboot');
+          this._rxBuf.length = 0;
+        } catch (e) {
+          log('enterRawRepl: no soft reboot banner', e.message);
+        }
+        ctrlARetries = 0;
+        while (ctrlARetries <= maxCtrlARetries) {
+          try {
+            await this.waitRawReplAfterSoftReboot(bannerBytes, bannerPromptBytes, 60000);
+            break;
+          } catch (e) {
+            if (ctrlARetries >= maxCtrlARetries) throw e;
+            ctrlARetries += 1;
+            log('enterRawRepl: post-reboot retry ctrl-A', ctrlARetries, e.message);
+            this._rxBuf.length = 0;
+            await this.sendCtrlA();
+          }
+        }
+      }
+
+      this.inRawRepl = true;
+      log('enterRawRepl: ready');
+    }
+
+    async rawPasteWrite(commandBytes) {
+      await this.writeBytes(new Uint8Array([0x05, 0x41, 0x01]));
+      const hdr = await this.readExact(2, 8000);
+      const windowSize = hdr[0] | (hdr[1] << 8);
+      let windowRemain = windowSize;
+      let i = 0;
+      while (i < commandBytes.length) {
+        while (windowRemain === 0) {
+          const b = await this.readExact(1, 15000);
+          if (b[0] === 0x01) {
+            windowRemain += windowSize;
+          } else if (b[0] === 0x04) {
+            await this.writeBytes(new Uint8Array([0x04]));
+            return;
+          } else {
+            throw new Error(`Unexpected byte during raw paste: 0x${b[0].toString(16)}`);
+          }
+        }
+        const n = Math.min(windowRemain, commandBytes.length - i);
+        await this.writeBytes(commandBytes.subarray(i, i + n));
+        windowRemain -= n;
+        i += n;
+      }
+      await this.writeBytes(new Uint8Array([0x04]));
+      await this.readUntil(new Uint8Array([0x04]), 30000);
+    }
+
+    async awaitRawReplExecPrompt(timeoutMs = 60000) {
+      const bannerPromptBytes = new TextEncoder().encode(RAW_REPL_BANNER + '>');
+      const deadline = Date.now() + timeoutMs;
+      while (Date.now() < deadline) {
+        const promptAt = bytesIndexOf(this._rxBuf, bannerPromptBytes);
+        if (promptAt >= 0) {
+          this._rxBuf.splice(0, promptAt + bannerPromptBytes.length);
+          return;
+        }
+        if (bufferEndsWithFriendlyRepl(this._rxBuf)) {
+          log('exec: friendly REPL before prompt, ctrl-A');
+          this._rxBuf.length = 0;
+          await this.sendCtrlA();
+        } else if (bufferLooksLikeEspRomBoot(this._rxBuf)) {
+          logDebug('exec: still in ROM boot, waiting…');
+        }
+        const rem = Math.max(1, deadline - Date.now());
+        const chunk = await this._readStreamChunk(Math.min(300, rem));
+        if (chunk && chunk.length) this._appendRx(chunk);
+        else await sleep(10);
+      }
+      const tail = decodeText(Uint8Array.from(this._rxBuf.slice(-240)));
+      throw new Error(`Timed out waiting for raw REPL prompt (tail: ${JSON.stringify(tail)})`);
+    }
+
+    async execRawNoFollow(commandBytes) {
+      log('execRawNoFollow', commandBytes.length, 'bytes');
+      await this.awaitRawReplExecPrompt(60000);
+
+      if (this.useRawPaste) {
+        await this.writeBytes(new Uint8Array([0x05, 0x41, 0x01]));
+        let data;
+        try {
+          data = await this.readExact(2, 3000);
+        } catch (_) {
+          this.useRawPaste = false;
+          data = null;
+        }
+        if (data) {
+          if (data[0] === 0x52 && data[1] === 0x01) {
+            log('exec: using raw paste mode');
+            await this.rawPasteWrite(commandBytes);
+            const ok = await this.readExact(2, 15000);
+            if (ok[0] !== 0x4f || ok[1] !== 0x4b) {
+              throw new Error(`Device did not return OK after paste (got ${decodeText(ok)})`);
+            }
+            log('exec: paste OK');
+            return;
+          }
+          if (data[0] === 0x52 && data[1] === 0x00) {
+            log('exec: raw paste not supported (R\\x00)');
+            this.useRawPaste = false;
+          } else {
+            log('exec: raw paste probe unexpected', describeBytes(data));
+            this.useRawPaste = false;
+            try {
+              await this.readUntil(new TextEncoder().encode(RAW_REPL_BANNER + '>'), 5000);
+            } catch (_) {
+              /* ignore */
+            }
+          }
+        }
+      }
+
+      for (let i = 0; i < commandBytes.length; i += 256) {
+        await this.writeBytes(commandBytes.subarray(i, Math.min(i + 256, commandBytes.length)));
+        await sleep(10);
+      }
+      log('exec: standard raw REPL write');
+      await this.writeBytes(new Uint8Array([0x04]));
+      const ok = await this.readExact(2, 15000);
+      if (ok[0] !== 0x4f || ok[1] !== 0x4b) {
+        throw new Error(`Device did not return OK (got ${decodeText(ok)})`);
+      }
+      log('exec: got OK');
+    }
+
+    async follow(timeoutMs = 30000) {
+      const out1 = await this.readUntil(new Uint8Array([0x04]), timeoutMs);
+      const stdout = decodeText(out1.slice(0, -1));
+      const out2 = await this.readUntil(new Uint8Array([0x04]), timeoutMs);
+      const stderr = decodeText(out2.slice(0, -1));
+      log('follow stdout', stdout.slice(0, 500));
+      if (stderr) log('follow stderr', stderr.slice(0, 500));
+      return { stdout, stderr };
+    }
+
+    async exec(command, timeoutMs = 30000) {
+      const preview =
+        typeof command === 'string' ? command.split('\n').slice(0, 3).join('\n') : '<bytes>';
+      log('exec', preview);
+      await this.ensureRawRepl();
+      const commandBytes =
+        typeof command === 'string' ? new TextEncoder().encode(command) : command;
+      await this.execRawNoFollow(commandBytes);
+      return this.follow(timeoutMs);
+    }
+
+    async readSettingsJson() {
+      log('readSettingsJson');
+      const code = [
+        'import json',
+        'try:',
+        "    f=open('settings.json','r')",
+        '    d=json.load(f)',
+        '    f.close()',
+        'except Exception:',
+        '    d={}',
+        'print(json.dumps(d))',
+      ].join('\n');
+      const { stdout, stderr } = await this.exec(code);
+      const text = (stdout || '').trim() || (stderr || '').trim();
+      if (!text) {
+        log('readSettingsJson: empty response');
+        return {};
+      }
+      const parsed = extractJsonObject(text);
+      log('readSettingsJson: ok', Object.keys(parsed));
+      return parsed;
+    }
+
+    async writeSettingsJson(settings) {
+      log('writeSettingsJson', settings);
+      const jsonText = JSON.stringify(settings);
+      const escaped = JSON.stringify(jsonText);
+      const code = [
+        'import json',
+        `s=json.loads(${escaped})`,
+        "f=open('settings.json','w')",
+        'f.write(s)',
+        'f.close()',
+        'import machine',
+        'machine.reset()',
+      ].join('\n');
+      await this.exec(code, 60000);
+    }
+  }
+
+  function serialSupported() {
+    return typeof navigator !== 'undefined' && 'serial' in navigator;
+  }
+
+  async function getGrantedPorts() {
+    if (!serialSupported()) return [];
+    return navigator.serial.getPorts();
+  }
+
+  async function requestPort() {
+    if (!serialSupported()) {
+      throw new Error('Web Serial not supported');
+    }
+    const granted = await navigator.serial.getPorts();
+    if (granted.length === 1) {
+      log('requestPort: reusing single granted port');
+      return granted[0];
+    }
+    log('requestPort: showing picker', { grantedCount: granted.length });
+    return navigator.serial.requestPort({ filters: ESP32_USB_FILTERS });
+  }
+
+  global.LedToolWebSerial = {
+    supported: serialSupported,
+    getGrantedPorts,
+    requestPort,
+    MicroPythonRawRepl,
+    _test: { bytesIndexOf, decodeText },
+  };
+})(typeof window !== 'undefined' ? window : globalThis);

tests/test_deploy_manifest.py

@@ -0,0 +1,52 @@
+"""Tests for deploy_manifest helpers (host Python)."""
+
+import json
+import os
+import tempfile
+import unittest
+
+from deploy_manifest import (
+    MANIFEST_FILENAME,
+    build_manifest_bytes,
+    normalize_remote_path,
+    parse_manifest,
+    sha256_hex_file,
+)
+
+
+class DeployManifestTests(unittest.TestCase):
+    def test_normalize_remote_path(self):
+        self.assertEqual(normalize_remote_path("/patterns/chase.py"), "patterns/chase.py")
+        self.assertEqual(normalize_remote_path("main.py"), "main.py")
+
+    def test_round_trip_manifest(self):
+        files = {"main.py": "abc", "patterns/x.py": "def"}
+        blob = build_manifest_bytes(files)
+        parsed = parse_manifest(blob)
+        self.assertEqual(parsed, files)
+        doc = json.loads(blob.decode())
+        self.assertEqual(doc["version"], 1)
+        self.assertEqual(doc["algorithm"], "sha256")
+
+    def test_parse_manifest_invalid(self):
+        self.assertEqual(parse_manifest(b"not json"), {})
+        self.assertEqual(parse_manifest(b'{"files": "nope"}'), {})
+
+    def test_sha256_hex_file(self):
+        with tempfile.NamedTemporaryFile(delete=False) as f:
+            f.write(b"hello")
+            path = f.name
+        try:
+            self.assertEqual(
+                sha256_hex_file(path),
+                "2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824",
+            )
+        finally:
+            os.unlink(path)
+
+    def test_manifest_filename(self):
+        self.assertEqual(MANIFEST_FILENAME, "file_hashes.json")
+
+
+if __name__ == "__main__":
+    unittest.main()

web.py

@@ -19,6 +19,7 @@ from flask import (
     redirect,
     url_for,
     flash,
+    send_from_directory,
 )
 
 
@@ -696,10 +697,119 @@ def handle_action():
     )
 
 
+def _static_dir() -> str:
+    return os.path.join(os.path.dirname(os.path.abspath(__file__)), "static")
+
+
+@app.route("/ports")
+def api_list_ports():
+    from host_ports import filter_port_dicts
+    from serial.tools import list_ports
+
+    ports = filter_port_dicts(
+        [
+            {"device": i.device, "description": i.description, "hwid": i.hwid}
+            for i in list_ports.comports()
+        ]
+    )
+    cli = os.path.join(os.path.dirname(os.path.abspath(__file__)), "cli.py")
+    return json.dumps({"ports": ports, "led_cli_exists": os.path.exists(cli)})
+
+
+@app.route("/settings", methods=["GET"])
+def api_read_settings():
+    import subprocess
+    import sys
+
+    port = (request.args.get("port") or "").strip()
+    if not port:
+        return json.dumps({"error": "port is required"}), 400
+    cli = os.path.join(os.path.dirname(os.path.abspath(__file__)), "cli.py")
+    result = subprocess.run(
+        [sys.executable, cli, "--port", port, "--show"],
+        capture_output=True,
+        text=True,
+        timeout=180,
+        cwd=os.path.dirname(cli),
+    )
+    settings = None
+    try:
+        settings = json.loads((result.stdout or "").strip())
+    except json.JSONDecodeError:
+        pass
+    return json.dumps(
+        {
+            "ok": result.returncode == 0,
+            "returncode": result.returncode,
+            "stdout": result.stdout,
+            "stderr": result.stderr,
+            "settings": settings,
+        }
+    )
+
+
+@app.route("/settings", methods=["POST"])
+def api_write_settings():
+    import subprocess
+    import sys
+
+    data = request.get_json(silent=True) or {}
+    port = str(data.get("port") or "").strip()
+    if not port:
+        return json.dumps({"error": "port is required"}), 400
+    cli = os.path.join(os.path.dirname(os.path.abspath(__file__)), "cli.py")
+    cmd = [sys.executable, cli, "--port", port]
+    flag_map = (
+        ("name", "--name"),
+        ("led_pin", "--pin"),
+        ("num_leds", "--leds"),
+        ("brightness", "--brightness"),
+        ("transport", "--transport"),
+        ("ssid", "--ssid"),
+        ("password", "--wifi-password"),
+        ("wifi_channel", "--wifi-channel"),
+        ("default", "--default"),
+    )
+    for key, flag in flag_map:
+        val = data.get(key)
+        if val is None:
+            continue
+        s = str(val).strip()
+        if s:
+            cmd.extend([flag, s])
+    cmd.append("--follow")
+    result = subprocess.run(
+        cmd,
+        capture_output=True,
+        text=True,
+        timeout=180,
+        cwd=os.path.dirname(cli),
+    )
+    return json.dumps(
+        {
+            "ok": result.returncode == 0,
+            "returncode": result.returncode,
+            "stdout": result.stdout,
+            "stderr": result.stderr,
+        }
+    )
+
+
+@app.route("/editor")
+def settings_editor():
+    """Static settings editor (Web Serial + host serial). Prefer this over the legacy form."""
+    return send_from_directory(_static_dir(), "settings_editor.html")
+
+
+@app.route("/static/<path:filename>")
+def settings_static(filename):
+    return send_from_directory(_static_dir(), filename)
+
+
 def main() -> None:
     # Bind to all interfaces so you can reach it from your LAN:
-    #   python web_app.py
+    #   python web.py
-    #   Then open: http://<pi-ip>:5000/
+    #   Then open: http://<pi-ip>:5000/editor
     app.run(host="0.0.0.0", port=5000, debug=False)