fix module frequency overriding

The `RadioInterface::freq` member was encapsulated with the `RadioInterface::getFreq()` function,
which could be overridden in child classes for some LoRa-modules.

src/mesh/RF95Interface.cpp

@@ -67,7 +67,7 @@ bool RF95Interface::init()
 #endif
     setTransmitEnable(false);
 
-    int res = lora->begin(freq, bw, sf, cr, syncWord, power, currentLimit, preambleLength);
+    int res = lora->begin(getFreq(), bw, sf, cr, syncWord, power, currentLimit, preambleLength);
     DEBUG_MSG("RF95 init result %d\n", res);
 
     // current limit was removed from module' ctor
@@ -119,7 +119,7 @@ bool RF95Interface::reconfigure()
     err = lora->setPreambleLength(preambleLength);
     assert(err == ERR_NONE);
 
-    err = lora->setFrequency(freq);
+    err = lora->setFrequency(getFreq());
     if (err != ERR_NONE)
         RECORD_CRITICALERROR(CriticalErrorCode_InvalidRadioSetting);
 

src/mesh/RadioInterface.cpp

@@ -318,14 +318,14 @@ void RadioInterface::applyModemConfig()
     // If user has manually specified a channel num, then use that, otherwise generate one by hashing the name
     const char *channelName = channels.getName(channels.getPrimaryIndex());
     int channel_num = channelSettings.channel_num ? channelSettings.channel_num - 1 : hash(channelName) % myRegion->numChannels;
-    freq = myRegion->freq + radioConfig.preferences.frequency_offset + myRegion->spacing * channel_num;
+    float freq = myRegion->freq + radioConfig.preferences.frequency_offset + myRegion->spacing * channel_num;
 
     DEBUG_MSG("Set radio: name=%s, config=%u, ch=%d, power=%d\n", channelName, channelSettings.modem_config, channel_num, power);
     DEBUG_MSG("Radio myRegion->freq: %f\n", myRegion->freq);
     DEBUG_MSG("Radio myRegion->spacing: %f\n", myRegion->spacing);
     DEBUG_MSG("Radio myRegion->numChannels: %d\n", myRegion->numChannels);
     DEBUG_MSG("Radio channel_num: %d\n", channel_num);
-    DEBUG_MSG("Radio frequency: %f\n", freq);
+    DEBUG_MSG("Radio frequency: %f\n", getFreq()); // the frequency could be overridden in RadioInterface::getFreq() for some modules
     DEBUG_MSG("Short packet time: %u msec\n", shortPacketMsec);
 
     saveChannelNum(channel_num);

src/mesh/RadioInterface.h

@@ -78,8 +78,6 @@ class RadioInterface
     void deliverToReceiver(MeshPacket *p);
 
   public:
-    float freq = 915.0;
-
     /** pool is the pool we will alloc our rx packets from
      */
     RadioInterface();
@@ -149,7 +147,7 @@ class RadioInterface
     /**
      * Get the frequency we saved.
      */
-    float getFreq();
+    virtual float getFreq();
 
     /// Some boards (1st gen Pinetab Lora module) have broken IRQ wires, so we need to poll via i2c registers
     virtual bool isIRQPending() { return false; }

src/mesh/SX1268Interface.h

@@ -8,8 +8,8 @@
 class SX1268Interface : public SX126xInterface<SX1268>
 {
   public:
-    /// Initializing the frequency of the SX1268 module regardless of the region
-    float freq = 433.0;
+    /// override frequency of the SX1268 module regardless of the region
+    virtual float getFreq() { return 433.0; }
 
     SX1268Interface(RADIOLIB_PIN_TYPE cs, RADIOLIB_PIN_TYPE irq, RADIOLIB_PIN_TYPE rst, RADIOLIB_PIN_TYPE busy, SPIClass &spi);
 };

src/mesh/SX126xInterface.cpp

@@ -52,7 +52,7 @@ bool SX126xInterface<T>::init()
 
     limitPower();
 
-    int res = lora.begin(freq, bw, sf, cr, syncWord, power, preambleLength, tcxoVoltage, useRegulatorLDO);
+    int res = lora.begin(getFreq(), bw, sf, cr, syncWord, power, preambleLength, tcxoVoltage, useRegulatorLDO);
     // \todo Display actual typename of the adapter, not just `SX126x`
     DEBUG_MSG("SX126x init result %d\n", res);
 
@@ -135,7 +135,7 @@ bool SX126xInterface<T>::reconfigure()
     err = lora.setPreambleLength(preambleLength);
     assert(err == ERR_NONE);
 
-    err = lora.setFrequency(freq);
+    err = lora.setFrequency(getFreq());
     if (err != ERR_NONE)
         RECORD_CRITICALERROR(CriticalErrorCode_InvalidRadioSetting);