[LLCC68] Changed default crystal to XTAL (#784)

src/modules/LLCC68/LLCC68.cpp

@@ -3,6 +3,7 @@
 
 LLCC68::LLCC68(Module* mod) : SX1262(mod) {
   chipType = RADIOLIB_LLCC68_CHIP_TYPE;
+  this->XTAL = true;
 }
 
 int16_t LLCC68::begin(float freq, float bw, uint8_t sf, uint8_t cr, uint8_t syncWord, int8_t pwr, uint16_t preambleLength, float tcxoVoltage, bool useRegulatorLDO) {

src/modules/LLCC68/LLCC68.h

@@ -32,11 +32,13 @@ class LLCC68: public SX1262 {
       \param syncWord 1-byte LoRa sync word. Defaults to RADIOLIB_SX126X_SYNC_WORD_PRIVATE (0x12).
       \param pwr Output power in dBm. Defaults to 10 dBm.
       \param preambleLength LoRa preamble length in symbols. Defaults to 8 symbols.
-      \param tcxoVoltage TCXO reference voltage to be set on DIO3. Defaults to 1.6 V, set to 0 to skip.
+      \param tcxoVoltage TCXO reference voltage to be set on DIO3. Defaults to 0 V (XTAL).
+      If you are seeing -706/-707 error codes, it likely means you are using a module with TCXO.
+      To use TCXO, either set this value to its reference voltage, or set SX126x::XTAL to false.
       \param useRegulatorLDO Whether to use only LDO regulator (true) or DC-DC regulator (false). Defaults to false.
       \returns \ref status_codes
     */
-    int16_t begin(float freq = 434.0, float bw = 125.0, uint8_t sf = 9, uint8_t cr = 7, uint8_t syncWord = RADIOLIB_SX126X_SYNC_WORD_PRIVATE, int8_t pwr = 10, uint16_t preambleLength = 8, float tcxoVoltage = 1.6, bool useRegulatorLDO = false);
+    int16_t begin(float freq = 434.0, float bw = 125.0, uint8_t sf = 9, uint8_t cr = 7, uint8_t syncWord = RADIOLIB_SX126X_SYNC_WORD_PRIVATE, int8_t pwr = 10, uint16_t preambleLength = 8, float tcxoVoltage = 0, bool useRegulatorLDO = false);
 
     // configuration methods