tests: create helper script to dump all mesh data from serial (#152)

* tests: create helper script to dump all mesh data from serial

* tests: use public callbacks for dump script

tests/dump.py

@@ -0,0 +1,77 @@
+#!/usr/bin/env python3
+import json, os, signal, sys, time, threading
+from datetime import datetime, timezone
+
+from meshtastic.serial_interface import SerialInterface
+from meshtastic.mesh_interface import MeshInterface
+from pubsub import pub
+
+PORT = os.environ.get("MESH_SERIAL", "/dev/ttyACM0")
+OUT = os.environ.get("MESH_DUMP_FILE", "meshtastic-dump.ndjson")
+
+# line-buffered append so you can tail -f safely
+f = open(OUT, "a", buffering=1, encoding="utf-8")
+
+
+def now():
+    return datetime.now(timezone.utc).isoformat()
+
+
+def write(kind, payload):
+    rec = {"ts": now(), "kind": kind, **payload}
+    f.write(json.dumps(rec, ensure_ascii=False, default=str) + "\n")
+
+
+# Connect to the node
+iface: MeshInterface = SerialInterface(PORT)
+
+
+# Packet callback: every RF/Mesh packet the node receives/decodes lands here
+def on_packet(packet, iface):
+    # 'packet' already includes decoded fields when available (portnum, payload, position, telemetry, etc.)
+    write("packet", {"packet": packet})
+
+
+# Node callback: topology/metadata updates (nodeinfo, hops, lastHeard, etc.)
+def on_node(node, iface):
+    write("node", {"node": node})
+
+
+iface.onReceive = on_packet
+pub.subscribe(on_node, "meshtastic.node")
+
+# Write a little header so you know what you captured
+try:
+    my = getattr(iface, "myInfo", None)
+    write(
+        "meta",
+        {
+            "event": "started",
+            "port": PORT,
+            "my_node_num": getattr(my, "my_node_num", None) if my else None,
+        },
+    )
+except Exception as e:
+    write("meta", {"event": "started", "port": PORT, "error": str(e)})
+
+
+# Keep the process alive until Ctrl-C
+def _stop(signum, frame):
+    write("meta", {"event": "stopping"})
+    try:
+        try:
+            pub.unsubscribe(on_node, "meshtastic.node")
+        except Exception:
+            pass
+        iface.close()
+    finally:
+        f.close()
+    sys.exit(0)
+
+
+signal.signal(signal.SIGINT, _stop)
+signal.signal(signal.SIGTERM, _stop)
+
+# Simple sleep loop; avoids busy-wait
+while True:
+    time.sleep(1)