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

@@ -32,6 +32,8 @@
 #include "STM32WLE5JCInterface.h"
 #endif
 
+Observable<uint32_t> RadioInterface::loraRxPacketObservable;
+
 #define RDEF(name, freq_start, freq_end, duty_cycle, spacing, power_limit, audio_permitted, frequency_switching, wide_lora)      \
     {                                                                                                                            \
         meshtastic_Config_LoRaConfig_RegionCode_##name, freq_start, freq_end, duty_cycle, spacing, power_limit, audio_permitted, \

src/mesh/RadioInterface.h

@@ -123,6 +123,9 @@ 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

@@ -509,6 +509,9 @@ void RadioLibInterface::completeSending()
     // that can take a long time
     auto p = sendingPacket;
     sendingPacket = NULL;
+#ifdef LED_LORA
+    digitalWrite(LED_LORA, LED_STATE_OFF);
+#endif
 
     if (p) {
         // Packet has been sent, count it toward our TX airtime utilization.
@@ -611,6 +614,10 @@ void RadioLibInterface::handleReceiveInterrupt()
 
             printPacket("Lora RX", mp);
 
+#ifdef LED_LORA
+            loraRxPacketObservable.notifyObservers(mp->from);
+#endif
+
             airTime->logAirtime(RX_LOG, rxMsec);
 
             deliverToReceiver(mp);
@@ -686,6 +693,9 @@ bool RadioLibInterface::startSend(meshtastic_MeshPacket *txp)
             enableInterrupt(isrTxLevel0);
             lastTxStart = millis();
             printPacket("Started Tx", txp);
+#ifdef LED_LORA
+            digitalWrite(LED_LORA, LED_STATE_ON);
+#endif
         }
 
         return res == RADIOLIB_ERR_NONE;