Harden nRF52 shutdown and radio recovery

src/helpers/NRF52Board.cpp

@@ -467,6 +467,16 @@ void NRF52Board::shutdownPeripherals() {
   // Power off LoRa
   radio_driver.powerOff();
 
+  // RadioLib's IRQ setup can leave DIO1 as a GPIO wake source. Once the radio
+  // is asleep that line may float or remain asserted, immediately waking an
+  // nRF52 that is trying to enter SYSTEMOFF. Release the interrupt channel and
+  // explicitly disable pin sensing; board-specific code can then arm only its
+  // intended wake source (for example, the SenseCAP user button or LPCOMP).
+  #ifdef P_LORA_DIO_1
+    detachInterrupt(P_LORA_DIO_1);
+    pinMode(P_LORA_DIO_1, INPUT);
+  #endif
+
   // Keep LoRa inactive during deepsleep
   #ifdef P_LORA_NSS
     digitalWrite(P_LORA_NSS, HIGH);

src/helpers/radiolib/CustomSX1262Wrapper.h

@@ -50,6 +50,7 @@ public:
   }
   uint8_t getSpreadingFactor() const override { return ((CustomSX1262 *)_radio)->spreadingFactor; }
   virtual void powerOff() override {
+    ((CustomSX1262 *)_radio)->standby();
     ((CustomSX1262 *)_radio)->sleep(false);
   }
 

src/helpers/radiolib/RadioLibWrappers.h

@@ -120,7 +120,7 @@ public:
         }
 
   void begin() override;
-  virtual void powerOff() { _radio->sleep(); }
+  virtual void powerOff() { _radio->standby(); _radio->sleep(); }
   int recvRaw(uint8_t* bytes, int sz) override;
   uint32_t getEstAirtimeFor(int len_bytes) override;
   bool startSendRaw(const uint8_t* bytes, int len) override;