[nRF24] Added TRNG support

src/modules/nRF24/nRF24.cpp

@@ -503,6 +503,12 @@ int16_t nRF24::setEncoding(uint8_t encoding) {
   return(ERR_NONE);
 }
 
+uint8_t nRF24::random() {
+  // nRF24 is unable to measure RSSI, hence no TRNG
+  // this method is implemented only for PhysicalLayer compatibility
+  return(0);
+}
+
 void nRF24::clearIRQ() {
   // clear status bits
   _mod->SPIsetRegValue(NRF24_REG_STATUS, NRF24_RX_DR | NRF24_TX_DS | NRF24_MAX_RT, 6, 4);

src/modules/nRF24/nRF24.h

@@ -464,6 +464,13 @@ class nRF24: public PhysicalLayer {
     */
     int16_t setEncoding(uint8_t encoding) override;
 
+    /*!
+     \brief Dummy random method, to ensure PhysicalLayer compatibility.
+
+     \returns Always returns 0.
+   */
+    uint8_t random();
+
 #ifndef RADIOLIB_GODMODE
   private:
 #endif