[RFM9x] Fixed frequency setting not saved (#253)

src/modules/SX127x/SX1276.cpp

@@ -116,8 +116,12 @@ int16_t SX1276::setFrequency(float freq) {
     }
   }
 
-  // set frequency
-  return(SX127x::setFrequencyRaw(freq));
+  // set frequency and if successful, save the new setting
+  int16_t state = SX127x::setFrequencyRaw(freq);
+  if(state == ERR_NONE) {
+    SX127x::_freq = freq;
+  }
+  return(state);
 }
 
 #endif

src/modules/SX127x/SX1277.cpp

@@ -117,7 +117,11 @@ int16_t SX1277::setFrequency(float freq) {
   }
 
   // set frequency and if successful, save the new setting
-  return(SX127x::setFrequencyRaw(freq));
+  int16_t state = SX127x::setFrequencyRaw(freq);
+  if(state == ERR_NONE) {
+    SX127x::_freq = freq;
+  }
+  return(state);
 }
 
 int16_t SX1277::setSpreadingFactor(uint8_t sf) {

src/modules/SX127x/SX1279.cpp

@@ -53,8 +53,12 @@ int16_t SX1279::beginFSK(float freq, float br, float freqDev, float rxBw, int8_t
 int16_t SX1279::setFrequency(float freq) {
   RADIOLIB_CHECK_RANGE(freq, 137.0, 960.0, ERR_INVALID_FREQUENCY);
 
-  // set frequency
-  return(SX127x::setFrequencyRaw(freq));
+  // set frequency and if successful, save the new setting
+  int16_t state = SX127x::setFrequencyRaw(freq);
+  if(state == ERR_NONE) {
+    SX127x::_freq = freq;
+  }
+  return(state);
 }
 
 #endif