Add curses dashboard and XIAO bridge examples; enhance stream parser for UTF-8 logging

examples/xiao_dashboard_bridge.py

@@ -0,0 +1,162 @@
+"""USB-to-Meshtastic bridge for the XIAO RP2040 curses dashboard.
+
+Install this file as ``main.py`` on the XIAO. UART0 talks to the Meshtastic
+radio on D6/D7, while newline-delimited JSON events and commands use USB stdio.
+"""
+
+import sys
+
+try:
+    import ujson as json
+except ImportError:
+    import json
+
+try:
+    import uselect as select
+except ImportError:
+    import select
+
+from machine import Pin, UART
+from time import sleep_ms, ticks_diff, ticks_ms
+
+from micromesh import PortNum, SerialInterface
+
+
+EVENT_PREFIX = "MMEVT "
+COMMAND_PREFIX = "MMCMD "
+
+
+def emit(event):
+    print(EVENT_PREFIX + json.dumps(event))
+    flush = getattr(sys.stdout, "flush", None)
+    if flush:
+        flush()
+
+
+def on_packet(packet):
+    event = {
+        "type": "packet",
+        "source": packet.from_,
+        "destination": packet.to,
+        "portnum": 0,
+        "text": "[encrypted]",
+        "is_text": False,
+    }
+    if packet.WhichOneof("payload_variant") == "decoded":
+        data = packet.decoded
+        event["portnum"] = data.portnum
+        if data.portnum == PortNum.TEXT_MESSAGE_APP:
+            try:
+                event["text"] = data.payload.decode("utf-8")
+            except UnicodeError:
+                event["text"] = repr(data.payload)
+            event["is_text"] = True
+        else:
+            event["text"] = "[port %d, %d bytes]" % (
+                data.portnum, len(data.payload)
+            )
+    emit(event)
+
+
+def node_event(info):
+    event = {"type": "node", "num": info.num}
+    if info.HasField("user"):
+        event["name"] = info.user.long_name or info.user.id or "unknown"
+        event["short"] = info.user.short_name or "--"
+        event["user_id"] = info.user.id
+    if info.HasField("snr"):
+        event["snr"] = info.snr
+    if info.HasField("last_heard"):
+        event["last_heard"] = info.last_heard
+    if info.HasField("hops_away"):
+        event["hops"] = info.hops_away
+    if info.HasField("device_metrics") and info.device_metrics.HasField("battery_level"):
+        event["battery"] = info.device_metrics.battery_level
+    return event
+
+
+def on_receive(message):
+    variant = message.WhichOneof("payload_variant") or "unknown"
+    emit({"type": "frame", "variant": variant})
+    if variant == "my_info":
+        emit({"type": "local", "num": message.my_info.my_node_num})
+    elif variant == "node_info":
+        emit(node_event(message.node_info))
+    elif variant == "config_complete_id":
+        emit({
+            "type": "config",
+            "complete": message.config_complete_id == mesh.config_id,
+            "nodes": len(mesh.nodes),
+        })
+
+
+def on_error(error, payload):
+    emit({"type": "error", "text": str(error), "bytes": len(payload)})
+
+
+uart = UART(
+    0,
+    baudrate=115200,
+    tx=Pin(0),  # XIAO D6
+    rx=Pin(1),  # XIAO D7
+    timeout=0,
+    rxbuf=2048,
+)
+
+mesh = SerialInterface(
+    uart,
+    on_receive=on_receive,
+    on_packet=on_packet,
+    on_log=lambda line: emit({"type": "status", "text": "radio: " + line}),
+    on_error=on_error,
+)
+
+command_poll = select.poll()
+command_poll.register(sys.stdin, select.POLLIN)
+
+
+def handle_commands():
+    for _ in command_poll.poll(0):
+        first = sys.stdin.read(1)
+        if first == "\x03":
+            # Never consume the interrupt mpremote uses to regain the REPL.
+            raise KeyboardInterrupt
+        # Dashboard commands are always newline-terminated. Reading the rest
+        # as one line also drains bytes MicroPython buffered after the first
+        # character but no longer reports through select.poll().
+        line = first + sys.stdin.readline()
+        line = line.strip()
+        if not line.startswith(COMMAND_PREFIX):
+            continue
+        try:
+            command = json.loads(line[len(COMMAND_PREFIX):])
+            kind = command.get("type")
+            if kind == "send":
+                text = command.get("text", "")
+                if text:
+                    mesh.sendText(text)
+                    emit({"type": "status", "text": "message queued"})
+            elif kind == "refresh":
+                mesh.request_config()
+                emit({"type": "status", "text": "configuration requested"})
+        except Exception as error:
+            emit({"type": "error", "text": "command: " + str(error)})
+
+
+emit({"type": "status", "text": "XIAO bridge starting"})
+mesh.connect()
+emit({"type": "status", "text": "configuration requested"})
+
+last_status = ticks_ms()
+while True:
+    mesh.poll()
+    handle_commands()
+    now = ticks_ms()
+    if ticks_diff(now, last_status) >= 5000:
+        emit({
+            "type": "heartbeat",
+            "connected": mesh.config_complete,
+            "nodes": len(mesh.nodes),
+        })
+        last_status = now
+    sleep_ms(10)