drb-edge-node/app/internal/mqtt_manager.py

@@ -213,7 +213,9 @@ class MQTTManager:
     async def _publish_checkin(self):
         from app.internal.discord_radio import radio_bot
         from app.internal.config_manager import load_node_config
+        from app.internal.op25_client import op25_client
         config = load_node_config()
+        devices = await op25_client.devices()
         payload = {
             "node_id": settings.node_id,
             "name": settings.node_name,
@@ -225,7 +227,12 @@ class MQTTManager:
             "is_overridden": config.override_system_id is not None and config.node_type != "portable",
             "override_system_id": config.override_system_id,
             "enforce_override_timeout": config.enforce_override_timeout,
+            "secondary_sdr_mode": config.secondary_sdr_mode,
         }
+        # Best-effort — the first node-initiated hardware-report field. Omit
+        # rather than guess if op25's control API is unreachable.
+        if devices is not None:
+            payload["sdr_count"] = devices.get("count")
         self._publish(self._t_checkin, payload, qos=1)
 
     def _publish(self, topic: str, payload: dict, qos: int = 0, retain: bool = False):

drb-edge-node/app/internal/op25_client.py

@@ -65,6 +65,16 @@ class OP25Client:
             logger.error(f"OP25 status failed: {e}")
             return None
 
+    async def devices(self) -> Optional[Dict[str, Any]]:
+        try:
+            async with httpx.AsyncClient(timeout=5) as client:
+                r = await client.get(f"{self.api_url}/op25/devices")
+                r.raise_for_status()
+                return r.json()
+        except Exception as e:
+            logger.error(f"OP25 device enumeration failed: {e}")
+            return None
+
     async def generate_config(self, config: Dict[str, Any]) -> bool:
         try:
             async with httpx.AsyncClient(timeout=10) as client:

drb-edge-node/app/main.py

@@ -224,6 +224,7 @@ async def on_config_push(payload: dict):
     hardware_preset = payload.pop("hardware_preset", None)
     ppm_override = payload.pop("ppm_override", None)
     node_type = payload.pop("node_type", None)
+    secondary_sdr_mode = payload.pop("secondary_sdr_mode", None)
     enforce_override_timeout = payload.pop("enforce_override_timeout", None)
     try:
         config = SystemConfig(**payload)
@@ -243,6 +244,8 @@ async def on_config_push(payload: dict):
         node_cfg.ppm_override = float(ppm_override)
     if node_type is not None:
         node_cfg.node_type = node_type
+    if secondary_sdr_mode is not None:
+        node_cfg.secondary_sdr_mode = secondary_sdr_mode
     if enforce_override_timeout is not None:
         node_cfg.enforce_override_timeout = bool(enforce_override_timeout)
     save_node_config(node_cfg)

drb-edge-node/app/models.py

@@ -34,6 +34,7 @@ class NodeConfig(BaseModel):
     hardware_preset: str = "rtl-sdr-v3"
     ppm_override: Optional[float] = None
     node_type: str = "fixed"  # fixed or portable
+    secondary_sdr_mode: str = "none"  # none | adsb | ais | op25_2 — requires a second physical SDR
     enforce_override_timeout: bool = True
     override_system_id: Optional[str] = None
     override_config: Optional[SystemConfig] = None

op25-container/Dockerfile

@@ -12,7 +12,7 @@ ENV DEBIAN_FRONTEND=noninteractive
 # Install system dependencies
 RUN apt-get update && \
     apt-get upgrade -y && \
-    apt-get install git pulseaudio pulseaudio-utils liquidsoap -y
+    apt-get install git pulseaudio pulseaudio-utils liquidsoap usbutils -y
 
 # Install custom PulseAudio system config (enables anonymous access for edge-node)
 COPY system.pa /etc/pulse/system.pa

op25-container/app/routers/op25_controller.py

@@ -1,6 +1,7 @@
 from fastapi import HTTPException, APIRouter
 import subprocess
 import os
+import re
 import signal
 import json
 from models import ConfigGenerator, DecodeMode, ChannelConfig, DeviceConfig, TrunkingConfig, TrunkingChannelConfig, TerminalConfig, MetadataConfig, MetadataStreamConfig, HARDWARE_PRESETS
@@ -69,6 +70,24 @@ def create_op25_router():
     async def get_status():
         return {"status": "running" if _is_running() else "stopped"}
 
+    @router.get("/devices")
+    async def list_sdr_devices():
+        """Enumerate connected SDR-looking USB devices via lsusb.
+
+        Same match heuristic as install.sh's one-shot host check — good enough
+        to answer "is a second SDR plugged in", not a serial-level device
+        binding (op25's DeviceConfig.args has no serial concept yet either).
+        """
+        devices = []
+        try:
+            out = subprocess.run(["lsusb"], capture_output=True, text=True, timeout=5).stdout
+            for line in out.splitlines():
+                if re.search(r"rtl2838|realtek.*283[28]|sdr", line, re.IGNORECASE):
+                    devices.append(line.strip())
+        except Exception as e:
+            LOGGER.warning(f"SDR device enumeration failed: {e}")
+        return {"count": len(devices), "devices": devices}
+
     @router.post("/generate-config")
     async def generate_config(generator: ConfigGenerator):
         try: