[Si443x] Implemented RF switch control

src/modules/Si443x/Si443x.cpp

@@ -222,6 +222,9 @@ int16_t Si443x::startTransmit(uint8_t* data, size_t len, uint8_t addr) {
   // write packet to FIFO
   _mod->SPIwriteRegisterBurst(SI443X_REG_FIFO_ACCESS, data, len);
 
+  // set RF switch (if present)
+  _mod->setRfSwitchState(true);
+
   // set mode to transmit
   _mod->SPIwriteRegister(SI443X_REG_OP_FUNC_CONTROL_1, SI443X_TX_ON);
 
@@ -246,6 +249,9 @@ int16_t Si443x::startReceive() {
   // clear interrupt flags
   clearIRQFlags();
 
+  // set RF switch (if present)
+  _mod->setRfSwitchState(false);
+
   // set mode to receive
   _mod->SPIwriteRegister(SI443X_REG_OP_FUNC_CONTROL_1, SI443X_RX_ON);
 
@@ -504,6 +510,10 @@ int16_t Si443x::setDataShaping(float sh) {
   }
 }
 
+void Si443x::setRfSwitchPins(RADIOLIB_PIN_TYPE rxEn, RADIOLIB_PIN_TYPE txEn) {
+  _mod->setRfSwitchPins(rxEn, txEn);
+}
+
 int16_t Si443x::setFrequencyRaw(float newFreq) {
   // set mode to standby
   int16_t state = standby();

src/modules/Si443x/Si443x.h

@@ -760,6 +760,16 @@ class Si443x: public PhysicalLayer {
     */
     int16_t setDataShaping(float sh);
 
+    /*!
+      \brief Some modules contain external RF switch controlled by two pins. This function gives RadioLib control over those two pins to automatically switch Rx and Tx state.
+      When using automatic RF switch control, DO NOT change the pin mode of rxEn or txEn from Arduino sketch!
+
+      \param rxEn RX enable pin.
+
+      \param txEn TX enable pin.
+    */
+    void setRfSwitchPins(RADIOLIB_PIN_TYPE rxEn, RADIOLIB_PIN_TYPE txEn);
+
 #ifndef RADIOLIB_GODMODE
   protected:
 #endif