Reduce status polling load and add 1Hz ready LED blink

src/main.py

@@ -1,4 +1,5 @@
 import logging
+import os
 import signal
 import threading
 import time
@@ -14,6 +15,33 @@ from webapp import WebPortal
 LOG = logging.getLogger("serial-bridge")
 
 
+def _configure_ready_led_blink() -> None:
+    led_bases = [
+        "/sys/class/leds/PWR",
+        "/sys/class/leds/led1",
+        "/sys/class/leds/ACT",
+        "/sys/class/leds/led0",
+    ]
+    for base in led_bases:
+        trigger_path = os.path.join(base, "trigger")
+        delay_on_path = os.path.join(base, "delay_on")
+        delay_off_path = os.path.join(base, "delay_off")
+        if not (os.path.exists(trigger_path) and os.path.exists(delay_on_path) and os.path.exists(delay_off_path)):
+            continue
+        try:
+            with open(trigger_path, "w", encoding="utf-8") as f:
+                f.write("timer\n")
+            with open(delay_on_path, "w", encoding="utf-8") as f:
+                f.write("500\n")
+            with open(delay_off_path, "w", encoding="utf-8") as f:
+                f.write("500\n")
+            LOG.info("Ready LED blink enabled on %s (1 Hz)", base)
+            return
+        except Exception as exc:
+            LOG.warning("Failed to configure LED blink on %s: %s", base, exc)
+    LOG.warning("No controllable LED found for ready blink")
+
+
 class Supervisor(threading.Thread):
     def __init__(self, state: AppState, nm: NetworkManager, rtc: RTCAndNTPManager) -> None:
         super().__init__(daemon=True)
@@ -133,6 +161,7 @@ def main() -> None:
             name="web-portal",
         )
         web_thread.start()
+        _configure_ready_led_blink()
 
         while not stop_event.wait(1):
             if not web_thread.is_alive():

src/webapp.py

@@ -2,6 +2,7 @@ import json
 import queue
 import subprocess
 import threading
+import time
 from typing import Any, Dict
 
 from flask import Flask, Response, jsonify, render_template, request, stream_with_context
@@ -24,6 +25,9 @@ class WebPortal:
         self.state = state
         self.network_manager = network_manager
         self.broadcaster = broadcaster
+        self._status_refresh_interval_s = 15.0
+        self._last_status_refresh_mono = 0.0
+        self._status_lock = threading.Lock()
         self.app = Flask(__name__, template_folder=template_folder, static_folder=static_folder)
         self._register_routes()
 
@@ -39,7 +43,11 @@ class WebPortal:
         @self.app.route("/api/status", methods=["GET"])
         def status() -> Response:
             try:
+                now = time.monotonic()
+                with self._status_lock:
+                    if now - self._last_status_refresh_mono >= self._status_refresh_interval_s:
                         self.network_manager.refresh_state()
+                        self._last_status_refresh_mono = now
                 return jsonify(self.state.snapshot())
             except Exception as exc:
                 self.state.update_status("Status update failed", str(exc))

templates/index.html

@@ -146,7 +146,7 @@
     document.getElementById('shutdownBtn').addEventListener('click', () => triggerSystemAction('shutdown'));
 
     refreshStatus();
-    setInterval(refreshStatus, 5000);
+    setInterval(refreshStatus, 15000);
   </script>
 </body>
 </html>