add crude mqtt read capabality

Hopi.py

@@ -4,6 +4,7 @@ from datetime import datetime, timezone
 
 from hopi.data_handler import PowerMeterDataHandler
 from hopi.gui_plotter import PlotConfig, RealtimePlotter
+from hopi.mqtt_client import MqttConfig, MqttJsonSubscriber
 from hopi.serial_client import ModbusRtuSerialClient, SerialConfig
 
 
@@ -15,9 +16,23 @@ READ_MAX_BYTES = 5 + (2 * NUM_WORDS)
 
 def build_arg_parser() -> argparse.ArgumentParser:
     parser = argparse.ArgumentParser(description="Read and print power meter values over Modbus RTU.")
+    parser.add_argument(
+        "--source",
+        choices=["usb", "mqtt"],
+        default="usb",
+        help="Data source: 'usb' (Modbus RTU over serial) or 'mqtt' (JSON over MQTT)",
+    )
+
     parser.add_argument("--port", default="/dev/ttyUSB0")
     parser.add_argument("--baud", type=int, default=9600)
     parser.add_argument("--timeout", type=float, default=0.1)
+
+    parser.add_argument("--mqtt-server", default="localhost:1883", help="MQTT broker host or host:port")
+    parser.add_argument("--mqtt-topic", default="pico-usb-host-modbus/modbus/readings", help="MQTT topic to subscribe to")
+    parser.add_argument("--mqtt-username", default=None)
+    parser.add_argument("--mqtt-password", default=None)
+    parser.add_argument("--mqtt-client-id", default=None)
+
     parser.add_argument("--daemon", action="store_true", help="Run continuously until stopped (Ctrl+C)")
     parser.add_argument("--csv", default="hopi_readings.csv", help="CSV output path for daemon mode")
     parser.add_argument("--interval", type=float, default=1.0, help="Seconds between reads in daemon mode")
@@ -29,16 +44,20 @@ def build_arg_parser() -> argparse.ArgumentParser:
 def main() -> None:
     args = build_arg_parser().parse_args()
 
+    handler = PowerMeterDataHandler()
+
+    if args.source == "usb":
         config = SerialConfig(port=args.port, baudrate=args.baud, timeout=args.timeout)
         client = ModbusRtuSerialClient(config)
-    handler = PowerMeterDataHandler()
+    else:
+        client = None
 
     if args.daemon:
         if args.timeout <= 0:
             raise ValueError("--timeout must be > 0")
         if args.interval <= 0:
             raise ValueError("--interval must be > 0")
-        if args.interval <= args.timeout:
+        if args.source == "usb" and args.interval <= args.timeout:
             raise ValueError("--interval must be > --timeout")
 
         t0 = time.monotonic()
@@ -50,6 +69,8 @@ def main() -> None:
             plotter = RealtimePlotter(series_names, config=PlotConfig(max_points=max(10, args.max_points)))
             plotter.open()
 
+        if args.source == "usb":
+            assert client is not None
             with client, handler.open_csv_logger(args.csv) as logger:
                 try:
                     while True:
@@ -82,6 +103,55 @@ def main() -> None:
                 except KeyboardInterrupt:
                     return
 
+        mqtt_cfg = MqttConfig(
+            server=args.mqtt_server,
+            topic=args.mqtt_topic,
+            username=args.mqtt_username,
+            password=args.mqtt_password,
+            client_id=args.mqtt_client_id,
+        )
+
+        with MqttJsonSubscriber(mqtt_cfg) as sub, handler.open_csv_logger(args.csv) as logger:
+            try:
+                while True:
+                    if plotter is not None and not plotter.is_open():
+                        return
+
+                    payload = sub.get(timeout=args.interval)
+                    if payload is None:
+                        if plotter is not None:
+                            plotter.process_events()
+                        continue
+
+                    readings = handler.decode_readings_from_mqtt_payload(payload)
+                    row = {"timestamp": datetime.now(timezone.utc).isoformat()}
+                    flat = handler.readings_to_flat_dict(readings)
+                    row.update(flat)
+                    logger.log(row)
+
+                    if plotter is not None:
+                        plotter.update(time.monotonic() - t0, flat)
+                        plotter.process_events()
+            except KeyboardInterrupt:
+                return
+
+    if args.source == "mqtt":
+        mqtt_cfg = MqttConfig(
+            server=args.mqtt_server,
+            topic=args.mqtt_topic,
+            username=args.mqtt_username,
+            password=args.mqtt_password,
+            client_id=args.mqtt_client_id,
+        )
+        with MqttJsonSubscriber(mqtt_cfg) as sub:
+            payload = sub.get(timeout=max(15.0, args.timeout))
+            if payload is None:
+                raise RuntimeError("No MQTT message received (timeout)")
+            readings = handler.decode_readings_from_mqtt_payload(payload)
+            handler.print_readings_json(readings)
+        return
+
+    assert client is not None
     with client:
         response = client.read_holding_registers(
             slave_id=SLAVE_ID,

hopi/data_handler.py

@@ -43,6 +43,63 @@ class ReadingsCsvLogger:
 class PowerMeterDataHandler:
     """Parses Modbus RTU responses and computes derived power metrics."""
 
+    def decode_readings_from_mqtt_payload(self, payload: dict) -> PowerMeterReadings:
+        """Decode a JSON dict coming from MQTT into PowerMeterReadings.
+
+        Accepts both this app's internal naming as well as the device's shorter keys.
+        Example device payload keys:
+        - annual_kwh, active_kwh, reactive_kwh, load_time_h, hours_day, device_addr
+        """
+
+        active_power = self._get_float(payload, "active_power_w")
+        rms_current = self._get_float(payload, "rms_current_a")
+        voltage = self._get_float(payload, "voltage_v")
+        frequency = self._get_float(payload, "frequency_hz")
+        power_factor = self._get_float(payload, "power_factor")
+
+        annual_power_consumption = self._get_float(
+            payload,
+            "annual_power_consumption_kwh",
+            "annual_kwh",
+        )
+        active_consumption = self._get_float(
+            payload,
+            "active_consumption_kwh",
+            "active_kwh",
+        )
+        reactive_consumption = self._get_float(
+            payload,
+            "reactive_consumption_kwh",
+            "reactive_kwh",
+        )
+
+        load_time_hours = self._get_float(payload, "load_time_hours", "load_time_h")
+        work_hours_per_day = self._get_int(payload, "work_hours_per_day", "hours_day")
+        device_address = self._get_int(payload, "device_address", "device_addr")
+
+        s_from_vi = self.apparent_from_vi(voltage, rms_current)
+        s_from_pf = self.apparent_from_pf(active_power, power_factor)
+        q_calculated = self.reactive_from_p_s(active_power, s_from_pf)
+        s_from_pq = self.apparent_from_p_q(active_consumption, reactive_consumption)
+
+        return PowerMeterReadings(
+            active_power_w=active_power,
+            rms_current_a=rms_current,
+            voltage_v=voltage,
+            frequency_hz=frequency,
+            power_factor=power_factor,
+            annual_power_consumption_kwh=annual_power_consumption,
+            active_consumption_kwh=active_consumption,
+            reactive_consumption_kwh=reactive_consumption,
+            load_time_hours=load_time_hours,
+            work_hours_per_day=work_hours_per_day,
+            device_address=device_address,
+            apparent_power_vi_va=s_from_vi,
+            apparent_power_pf_va=s_from_pf,
+            reactive_power_var=q_calculated,
+            apparent_consumption_kvah=s_from_pq,
+        )
+
     def parse_read_holding_registers_response(self, response: bytes) -> List[int]:
         # Response layout: [slave][func][byte_count][data...][crc_lo][crc_hi]
         # We keep validation intentionally lightweight to match prior script behavior.
@@ -196,3 +253,25 @@ class PowerMeterDataHandler:
         if active_kwh == 0 and reactive_kwh == 0:
             return 0.0
         return math.sqrt(active_kwh**2 + reactive_kwh**2)
+
+    @staticmethod
+    def _get_float(payload: dict, *keys: str, default: float = 0.0) -> float:
+        for key in keys:
+            if key in payload and payload[key] is not None:
+                value = payload[key]
+                try:
+                    return float(value)
+                except (TypeError, ValueError):
+                    return default
+        return default
+
+    @staticmethod
+    def _get_int(payload: dict, *keys: str, default: int = 0) -> int:
+        for key in keys:
+            if key in payload and payload[key] is not None:
+                value = payload[key]
+                try:
+                    return int(value)
+                except (TypeError, ValueError):
+                    return default
+        return default

hopi/mqtt_client.py

@@ -0,0 +1,139 @@
+from __future__ import annotations
+
+import json
+import queue
+import threading
+from dataclasses import dataclass
+from typing import Any, Dict, Optional
+
+
+@dataclass(frozen=True)
+class MqttConfig:
+    server: str  # host or host:port
+    topic: str
+    username: Optional[str] = None
+    password: Optional[str] = None
+    client_id: Optional[str] = None
+    keepalive: int = 60
+
+
+def _parse_server(server: str) -> tuple[str, int]:
+    server = server.strip()
+    if not server:
+        raise ValueError("MQTT server must not be empty")
+
+    # Accept host or host:port.
+    if ":" in server:
+        host, port_s = server.rsplit(":", 1)
+        host = host.strip()
+        if not host:
+            raise ValueError("MQTT server host must not be empty")
+        try:
+            port = int(port_s)
+        except ValueError as exc:
+            raise ValueError("MQTT server port must be an integer") from exc
+        return host, port
+
+    return server, 1883
+
+
+class MqttJsonSubscriber:
+    """Subscribes to a topic and yields decoded JSON payloads."""
+
+    def __init__(self, config: MqttConfig):
+        self._config = config
+        self._queue: queue.Queue[Dict[str, Any]] = queue.Queue(maxsize=1000)
+        self._client = None
+
+    def __enter__(self) -> "MqttJsonSubscriber":
+        self.open()
+        return self
+
+    def __exit__(self, exc_type, exc, tb) -> None:
+        self.close()
+
+    def open(self) -> None:
+        if self._client is not None:
+            return
+
+        try:
+            import paho.mqtt.client as mqtt
+        except Exception as exc:  # pragma: no cover
+            raise RuntimeError(
+                "MQTT requires paho-mqtt. Install it (pip install paho-mqtt) or run with --source usb."
+            ) from exc
+
+        host, port = _parse_server(self._config.server)
+
+        client = mqtt.Client(client_id=self._config.client_id)
+        if self._config.username is not None:
+            client.username_pw_set(self._config.username, self._config.password)
+
+        connected = threading.Event()
+        connect_rc: dict[str, int] = {"rc": -1}
+
+        def on_connect(_client, _userdata, _flags, rc):
+            connect_rc["rc"] = int(rc)
+            connected.set()
+            if rc != 0:
+                return
+            _client.subscribe(self._config.topic)
+
+        def on_message(_client, _userdata, msg):
+            try:
+                payload = msg.payload.decode("utf-8", errors="strict")
+                data = json.loads(payload)
+                if isinstance(data, dict):
+                    try:
+                        self._queue.put_nowait(data)
+                    except queue.Full:
+                        # Drop oldest to keep latest values moving.
+                        try:
+                            _ = self._queue.get_nowait()
+                        except queue.Empty:
+                            pass
+                        try:
+                            self._queue.put_nowait(data)
+                        except queue.Full:
+                            pass
+            except Exception:
+                # Ignore invalid JSON messages.
+                return
+
+        client.on_connect = on_connect
+        client.on_message = on_message
+
+        client.connect(host, port, keepalive=self._config.keepalive)
+        client.loop_start()
+
+        if not connected.wait(timeout=5.0):
+            client.loop_stop()
+            client.disconnect()
+            raise RuntimeError("MQTT connect timed out")
+
+        if connect_rc["rc"] != 0:
+            client.loop_stop()
+            client.disconnect()
+            raise RuntimeError(f"MQTT connect failed (rc={connect_rc['rc']})")
+
+        self._client = client
+
+    def close(self) -> None:
+        client = self._client
+        self._client = None
+        if client is None:
+            return
+        try:
+            client.loop_stop()
+        finally:
+            try:
+                client.disconnect()
+            except Exception:
+                pass
+
+    def get(self, *, timeout: Optional[float] = None) -> Optional[Dict[str, Any]]:
+        """Get the next JSON message dict, or None on timeout."""
+        try:
+            return self._queue.get(timeout=timeout)
+        except queue.Empty:
+            return None

requirements.txt

@@ -1,2 +1,3 @@
 pyserial>=3.5
 matplotlib>=3.5
+paho-mqtt>=1.6