STM32WLx: add PREAMBLE_DETECTED to reported irq flags

src/helpers/radiolib/CustomSTM32WLx.h

@@ -2,16 +2,18 @@
 
 #include <RadioLib.h>
 
-#define SX126X_IRQ_HEADER_VALID                     0b0000010000  //  4     4     valid LoRa header received
-#define SX126X_IRQ_PREAMBLE_DETECTED           0x04
-
 class CustomSTM32WLx : public STM32WLx {
   public:
     CustomSTM32WLx(STM32WLx_Module *mod) : STM32WLx(mod) { }
 
+    int16_t startReceive() override {
+      // include the PREAMBLE_DETECTED irq bit in reported flags
+      return STM32WLx::startReceive(RADIOLIB_SX126X_RX_TIMEOUT_INF, RADIOLIB_IRQ_RX_DEFAULT_FLAGS | (1UL << RADIOLIB_IRQ_PREAMBLE_DETECTED), RADIOLIB_IRQ_RX_DEFAULT_MASK, 0);
+    }
+
     bool isReceiving() {
       uint16_t irq = getIrqFlags();
-      bool detected = (irq & SX126X_IRQ_HEADER_VALID) || (irq & SX126X_IRQ_PREAMBLE_DETECTED);
+      bool detected = (irq & RADIOLIB_SX126X_IRQ_HEADER_VALID) || (irq & RADIOLIB_SX126X_IRQ_PREAMBLE_DETECTED);
       return detected;
     }
 };