[Si443x] Added direct reception support

src/modules/Si443x/Si443x.cpp

@@ -571,6 +571,14 @@ int16_t Si443x::getChipVersion() {
   return(_mod->SPIgetRegValue(SI443X_REG_DEVICE_VERSION));
 }
 
+void Si443x::setDirectAction(void (*func)(void)) {
+  setIrqAction(func);
+}
+
+void Si443x::readBit(RADIOLIB_PIN_TYPE pin) {
+  updateDirectBuffer((uint8_t)digitalRead(pin));
+}
+
 int16_t Si443x::setFrequencyRaw(float newFreq) {
   // set mode to standby
   int16_t state = standby();

src/modules/Si443x/Si443x.h

@@ -799,6 +799,20 @@ class Si443x: public PhysicalLayer {
    */
     int16_t getChipVersion();
 
+    /*!
+      \brief Set interrupt service routine function to call when data bit is receveid in direct mode.
+
+      \param func Pointer to interrupt service routine.
+    */
+    void setDirectAction(void (*func)(void));
+
+    /*!
+      \brief Function to read and process data bit in direct reception mode.
+
+      \param pin Pin on which to read.
+    */
+    void readBit(RADIOLIB_PIN_TYPE pin);
+
 #if !defined(RADIOLIB_GODMODE) && !defined(RADIOLIB_LOW_LEVEL)
   protected:
 #endif