Lora led rx (#10674)

* add optional LED_LORA to indicate LoRa TX

* Briefly flash LED_LORA on packet RX

---------

Co-authored-by: Ben Meadors <benmmeadors@gmail.com>

src/mesh/RadioInterface.cpp

@@ -63,6 +63,8 @@ const RegionProfile PROFILE_HAM_20KHZ = {PRESETS_TINY, 0, 0.0022f, false, true,
 // Ham '100kHz' profile. 62.5kHz bandwidth coerced to 100kHz via padding.
 const RegionProfile PROFILE_HAM_100KHZ = {PRESETS_NARROW, 0, 0.01875f, false, true, 0, 1, 1};
 
+Observable<uint32_t> RadioInterface::loraRxPacketObservable;
+
 #define RDEF(name, freq_start, freq_end, duty_cycle, power_limit, frequency_switching, wide_lora, profile_ptr, default_preset,   \
              override_slot)                                                                                                      \
     {                                                                                                                            \
@@ -1365,4 +1367,4 @@ size_t RadioInterface::beginSending(meshtastic_MeshPacket *p)
 
     sendingPacket = p;
     return p->encrypted.size + sizeof(PacketHeader);
-}
+}

src/mesh/RadioInterface.h

@@ -128,6 +128,9 @@ class RadioInterface
 
     virtual ~RadioInterface() {}
 
+    /// Fires once per valid received LoRa packet (arg = sender NodeNum). Used e.g. to flash LED_LORA.
+    static Observable<uint32_t> loraRxPacketObservable;
+
     /**
      * Coerce LoRa config fields (bandwidth/spread_factor) derived from presets.
      * This is used during early bootstrapping so UIs that display these fields directly remain consistent.

src/mesh/RadioLibInterface.cpp

@@ -614,6 +614,10 @@ void RadioLibInterface::handleReceiveInterrupt()
 
             printPacket("Lora RX", mp);
 
+#ifdef LED_LORA
+            loraRxPacketObservable.notifyObservers(mp->from);
+#endif
+
             airTime->logAirtime(RX_LOG, rxMsec);
 
             deliverToReceiver(mp);