Use 50% scale for ESP32 sine wave generator for lower distortion

main/ESPAudio.cpp

@@ -219,9 +219,11 @@ bool Audio::selfTest(){
 	{
 		ESP_LOGI(FNAME,"MCP4018 digital Poti found");
 	}
-	float setvolume = default_volume.get();
-	speaker_volume = vario_mode_volume = s2f_mode_volume = setvolume;
-	ESP_LOGI(FNAME,"default volume: %f", speaker_volume );
+	float setvolume = 50.0;
+
+	if( hardwareRevision.get() >= XCVARIO_21 )
+		DigitalPoti->setHalfScale();          // double amplitude from ESP32 for better sound
+
 	_alarm_mode = true;
 	writeVolume( 50.0 );
 	float getvolume;
@@ -231,15 +233,23 @@ bool Audio::selfTest(){
 		ESP_LOGI(FNAME,"readWiper returned error");
 		return false;
 	}
-	if( (int)getvolume != 49 )
+	if( std::abs( getvolume - setvolume ) > 2.0 )
 	{
 		ESP_LOGI(FNAME,"readWiper returned wrong setting set=%f get=%f", setvolume, getvolume );
 		ret = false;
 	}
-	else
+	else{
+		ESP_LOGI(FNAME,"readWiper: OK");
 		ret = true;
+	}
+
 	bool fadein=false;
 	_alarm_mode = false;
+
+	setvolume = default_volume.get();
+	speaker_volume = vario_mode_volume = s2f_mode_volume = setvolume;
+	ESP_LOGI(FNAME,"default volume: %f", speaker_volume );
+	writeVolume( setvolume );
 	//	while(1){    // uncomment for continuous self test
 	ESP_LOGI(FNAME,"Min F %f, Max F %f", minf, maxf );
 	for( float f=minf; f<maxf*1.25; f=f*1.03){
@@ -490,7 +500,6 @@ void Audio::calcS2Fmode( bool recalc ){
 	}
 }
 
-
 void  Audio::evaluateChopping(){
 	if(
 			(chopping_mode.get() == BOTH_CHOP) ||
@@ -793,7 +802,7 @@ void Audio::restart()
 	dac_cosine_enable(_ch);
 	dac_offset_set(_ch, 0 );
 	dac_invert_set(_ch, 2 );    // invert MSB to get sine waveform
-	dac_scale_set(_ch, 2 );
+	hardwareRevision.get() >= XCVARIO_21 ? dac_scale_set(_ch, 1 ) : dac_scale_set(_ch, 2 );   // new hardware can accept 50% scale -> better sound
 	enableAmplifier( true );
 	dacEnable();
 }

main/Poti.h

@@ -14,6 +14,7 @@ class Poti
   virtual bool readVolume( float& val ) = 0;
   virtual bool writeVolume( float val ) = 0;
   virtual bool haveDevice() = 0;
+  virtual void setHalfScale() = 0;
 private:
   virtual int  getRange() = 0;
   virtual float getInvRange() = 0;

main/SetupMenu.cpp

@@ -557,8 +557,8 @@ void SetupMenu::down(int count){
 		else{  // Volume
 			float vol = audio_volume.get();
 			for( int i=0; i<count; i++ )
-				vol = vol * 0.83;
-			if( vol<3.0 )
+				vol = vol * 0.77;
+			if( vol<1.5 )            // allow smaller volumes to better support new 50% scale mode of ESP32 sine generator (default is 25%)
 				vol=0;
 			audio_volume.set( vol );
 			// ESP_LOGI(FNAME,"NEW DN VOL: %f", vol );
@@ -598,10 +598,10 @@ void SetupMenu::up(int count){
 		}
 		else{  // Volume
 			float vol = audio_volume.get();
-			if( vol<3.0 )
-				vol=3.0;
+			if( vol<1.5 )
+				vol=1.5;
 			for( int i=0; i<count; i++ )
-				vol = vol * 1.17;
+				vol = vol * 1.33;
 			if( vol > max_volume.get() )
 				vol = max_volume.get();
 			audio_volume.set( vol );

main/cat5171.cpp

@@ -9,6 +9,7 @@ CAT5171::CAT5171()
 	_noDevice = false;
 	wiper = CAT5171RANGE/2;
 	bus = 0;
+	_scale = 100;
 }
 
 bool CAT5171::begin()
@@ -79,19 +80,18 @@ bool CAT5171::writeWiper( int val ) {
 bool CAT5171::readVolume( float &val ) {
 	int ival;
 	if ( readWiper( ival ) ) {
-		val = (float)(100 * ival) * getInvRange();
+		val = (float)(_scale * ival) * getInvRange();
 		return true;
 	}
 	return false;
 }
 
 bool CAT5171::writeVolume( float val ) {
 	int ival = (int)(val * getRange());
-	ival /= 100;
+	ival /= _scale;
 	return writeWiper( ival );
 }
 
-
 bool CAT5171::reset() {
     ESP_LOGI(FNAME,"CAT5171 reset");
 	esp_err_t err = bus->write2bytes( CAT5171_I2C_ADDR, 0x60, 128 );  // 0x40 = RS = midscale

main/cat5171.h

@@ -32,6 +32,7 @@ class CAT5171: public Poti
   bool writeVolume( float val );
   bool reset();
   bool haveDevice();
+  void setHalfScale() { _scale = 200; };
 
 private:
   bool readWiper( int& val );
@@ -44,6 +45,7 @@ class CAT5171: public Poti
   int  errorcount;
   bool  _noDevice;
   int wiper;  // only bit 0..7 supported
+  int _scale;
 };
 
 #endif

main/mcp4018.cpp

@@ -9,6 +9,7 @@ MCP4018::MCP4018()
 	_noDevice = false;
 	wiper = MCP4018RANGE/2;
 	bus = 0;
+	_scale = 100;
 }
 
 bool MCP4018::begin()
@@ -78,7 +79,7 @@ bool MCP4018::writeWiper( int val ) {
 bool MCP4018::readVolume( float &val ) {
 	int ival;
 	if ( readWiper( ival ) ) {
-		val = (float)(100 * ival) * getInvRange();
+		val = (float)(_scale * ival) * getInvRange();
 		return true;
 	}
 	else
@@ -89,6 +90,6 @@ bool MCP4018::readVolume( float &val ) {
 
 bool MCP4018::writeVolume( float val ) {
 	int ival = (int)(val * getRange());
-	ival /= 100;
+	ival /= _scale;
 	return writeWiper( ival );
 }

main/mcp4018.h

@@ -31,6 +31,7 @@ class MCP4018: public Poti
   bool readVolume( float& val );
   bool writeVolume( float val );
   bool haveDevice();
+  void setHalfScale() { _scale = 200; };
 
 private:
   bool readWiper( int& val );
@@ -43,6 +44,7 @@ class MCP4018: public Poti
   int  errorcount;
   bool  _noDevice;
   int wiper;  // only bit 0..7 supported
+  int _scale;
 };
 
 #endif