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examples/01_SERIAL_MONITOR/B_TX/B_TX.ino

@@ -1,6 +1,6 @@
 #include <QN8066.h>
 
-#define FREQ 106.8
+#define FREQ 1067   // Frequency: 106.7 MHz
 
 QN8066 dv;
 
@@ -53,10 +53,10 @@ void setup() {
 
 
   dv.setTxInputImpedance(0);  // 0=10; 1 = 20; 2=40 (default); 3=80. Kohms.
-  dv.setTxInputBufferGain(5); // With input inpedance  0 (10K), and input buffer 5, the gain shoud be 18dB
+  // dv.setTxInputBufferGain(5); // With input inpedance  0 (10K), and input buffer 5, the gain shoud be 18dB
   dv.setTxSoftClipping(true);
-  dv.setTxDigitalGain(2); // TX digital gain => 2 = 2dB  (default is 0 dB)
-  dv.setTxFrequencyDerivation(200); // Valid valued from 0 to 255
+  //  dv.setTxDigitalGain(2); // TX digital gain => 2 = 2dB  (default is 0 dB)
+  // dv.setTxFrequencyDerivation(200); // Valid valued from 0 to 255
 
   sprintf(str, "\n\nBroadcasting...");
   Serial.print(str);

src/QN8066.cpp

@@ -154,9 +154,12 @@ void QN8066::setRX() {
 /**
  * @ingroup group04 Start TX
  * @brief Sets the TX mode
+ * @details To avoid working with the float data type, the frequency parameter must be the desired frequency multiplied by 10.
+ * @details For example, if the user wants to tune to 106.7 MHz, the parameter to be sent is 1067.
+ * @details This approach reduces the size of the final code (binary) as well as avoids the inaccuracies of floating-point mathematical operations.
  * @param frequency - Frequency to be set
  */
-void QN8066::setTX(float frequency) {
+void QN8066::setTX(uint16_t frequency) {
   this->setRegister(QN_SYSTEM1, 0B11100011); // RESET the SYSTEM
   delay(200);
 
@@ -165,14 +168,11 @@ void QN8066::setTX(float frequency) {
   this->setRegister(QN_CCA, 0B00010000);
 
   // Sets the crystal oscillator divider
-  this->setRegister(QN_XTAL_DIV0,
-                    this->xtal_div & 0xFF); // Lower 8 bits of xtal_div[10:0].
-  this->setRegister(QN_XTAL_DIV1,
-                    (this->xtal_div >> 8) |
-                        0B0001000); // Higher 3 bits of xtal_div[10:0].
+  this->setRegister(QN_XTAL_DIV0, this->xtal_div & 0xFF); // Lower 8 bits of xtal_div[10:0].
+  this->setRegister(QN_XTAL_DIV1, (this->xtal_div >> 8) |  0B0001000); // Higher 3 bits of xtal_div[10:0].
 
   // Set frequency
-  int16_t auxFreq = (int16_t)((frequency - 60) / 0.05);
+  int16_t auxFreq = (frequency - 600)  * 2;
   this->setRegister(QN_INT_CTRL, 0B00100000 | auxFreq >> 8);
   this->setRegister(QN_TXCH, 0B11111111 & auxFreq);
 

src/QN8066.h

@@ -793,7 +793,7 @@ class QN8066 {
    */
   void setRX();
 
-  void setTX(float frequency); // RESET the system and set to TX mode at a given frequency
+  void setTX(uint16_t frequency); // RESET the system and set to TX mode at a given frequency
 
 
   void setTxStereo(bool value = true);