Improve the register switch

Allow it to transpose either -1, +/-0, or +1 octave without affecting the tone spacing and clean, independent of the pitch pot setting

Open_Theremin_V3/application.cpp

@@ -131,11 +131,11 @@ unsigned long Application::GetVolumeMeasurement()
 
   TCNT0=0;
   TCNT1=49911;
-  TCCR0B = (1<<CS02) | (1<<CS01) | (1<<CS00);	 // //External clock source on T0 pin. Clock on rising edge.
+  TCCR0B = (1<<CS02) | (1<<CS01) | (1<<CS00);  // //External clock source on T0 pin. Clock on rising edge.
   TIFR1  = (1<<TOV1);        //Timer1 INT Flag Reg: Clear Timer Overflow Flag
 
 while(!(TIFR1&((1<<TOV1)))); // on Timer 1 overflow (1s)
-  TCCR0B = 0;	 // Stop TimerCounter 0
+  TCCR0B = 0;  // Stop TimerCounter 0
  unsigned long frequency = TCNT0; // get counter 0 value
  unsigned long temp = (unsigned long)timer_overflow_counter; // and overflow counter
 
@@ -164,7 +164,7 @@ void Application::loop() {
   uint16_t pitchPotValue = 0;
   int registerPotValue,registerPotValueL = 0;
   int wavePotValue,wavePotValueL = 0;
-  uint8_t registerValue = 0;
+  uint8_t registerValue = 2;
 
 
 
@@ -179,7 +179,19 @@ void Application::loop() {
   if (((wavePotValue-wavePotValueL) >= HYST_VAL) || ((wavePotValueL-wavePotValue) >= HYST_VAL)) wavePotValueL=wavePotValue;
 
   vWavetableSelector=wavePotValueL>>7;
-  registerValue=4-(registerPotValueL>>8);  
+
+  // New register pot configuration:
+  // Left = -1 octave, Center = +/- 0, Right = +1 octave
+  if(registerPotValue > 681) 
+  {
+    registerValue = 1;
+  } else if(registerPotValue < 342)
+  {
+    registerValue = 3;
+  } else 
+  {
+    registerValue = 2;
+  }
 
   if (_state == PLAYING && HW_BUTTON_PRESSED) {
     _state = CALIBRATING;
@@ -251,7 +263,7 @@ void Application::loop() {
     // set wave frequency for each mode
     switch (_mode) {
       case MUTE : /* NOTHING! */;                                        break;
-      case NORMAL      : setWavetableSampleAdvance((pitchCalibrationBase-pitch_v)/registerValue+2048-(pitchPotValue<<2)); break;
+      case NORMAL      : setWavetableSampleAdvance(((pitchCalibrationBase-pitch_v)+2048-(pitchPotValue<<2))>>registerValue); break;
     };
     
   //  HW_LED2_OFF;
@@ -512,7 +524,3 @@ void Application::delay_NOP(unsigned long time) {
       __asm__ __volatile__ ("nop");
   }
 }
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