Added filter 'tone' examples and trimmed fat in balance examples

The 'tone' filter examples are both using calcBiquad(..); but one uses
AudioFilterBiquad and other uses SGTL5000 PEQ filters. Had included code
for volume level control optionally and decided to drop it from both.

examples/CalcBiquadToneControl/CalcBiquadToneControl.ino

+// Tone example using AudioFilterBiquad object and calcBiquad filter calculator routine.
+
+#include <Audio.h>
+#include <Wire.h>
+#include <SD.h>
+
+const int myInput = AUDIO_INPUT_LINEIN;
+// const int myInput = AUDIO_INPUT_MIC;
+
+int BassFilter_L[]={0,0,0,0,0,0,0,0};
+int BassFilter_R[]={0,0,0,0,0,0,0,0};
+int TrebFilter_L[]={0,0,0,0,0,0,0,0};
+int TrebFilter_R[]={0,0,0,0,0,0,0,0};
+
+int updateFilter[5];
+ 
+AudioInputI2S        audioInput;         // audio shield: mic or line-in
+AudioFilterBiquad    filterBass_L(BassFilter_L);
+AudioFilterBiquad    filterBass_R(BassFilter_R);
+AudioFilterBiquad    filterTreb_L(TrebFilter_L);
+AudioFilterBiquad    filterTreb_R(TrebFilter_R);
+AudioOutputI2S       audioOutput;        // audio shield: headphones & line-out
+
+// Create Audio connections between the components
+//
+AudioConnection c1(audioInput,0,filterBass_L,0);
+AudioConnection c2(audioInput,1,filterBass_R,0);
+AudioConnection c3(filterBass_L,0,filterTreb_L,0);
+AudioConnection c4(filterBass_R,0,filterTreb_R,0);
+AudioConnection c5(filterTreb_L,0,audioOutput,0);
+AudioConnection c6(filterTreb_R,0,audioOutput,1);
+
+// Create an object to control the audio shield.
+// 
+AudioControlSGTL5000 audioShield;
+
+void setup() {
+  // Audio connections require memory to work.  For more
+  // detailed information, see the MemoryAndCpuUsage example
+  AudioMemory(12);
+  // Enable the audio shield, select the input and set the output volume.
+  audioShield.enable();
+  audioShield.inputSelect(myInput);
+  audioShield.volume(75);
+  audioShield.unmuteLineout();
+
+  calcBiquad(FILTER_PARAEQ,110,0,0.2,2147483648,44100,updateFilter);
+  filterBass_L.updateCoefs(updateFilter);
+  filterBass_R.updateCoefs(updateFilter);
+  calcBiquad(FILTER_PARAEQ,4400,0,0.167,2147483648,44100,updateFilter);
+  filterTreb_L.updateCoefs(updateFilter);
+  filterTreb_R.updateCoefs(updateFilter);
+}
+
+elapsedMillis chgMsec=0;
+float tone1=0;
+
+void loop() {
+  // every 10 ms, check for adjustment the tone & vol
+  if (chgMsec > 10) { // more regular updates for actual changes seems better.
+    
+    float tone2=analogRead(15);
+    tone2=floor(((tone2-512)/512)*70)/10;
+    if(tone2!=tone1)
+    {
+      // calcBiquad(FilterType,FrequencyC,dBgain,Q,QuantizationUnit,SampleRate,int*);
+      calcBiquad(FILTER_PARAEQ,110,-tone2,0.2,2147483648,44100,updateFilter);
+      filterBass_L.updateCoefs(updateFilter);
+      filterBass_R.updateCoefs(updateFilter);
+      calcBiquad(FILTER_PARAEQ,4400,tone2,0.167,2147483648,44100,updateFilter);
+      filterTreb_L.updateCoefs(updateFilter);
+      filterTreb_R.updateCoefs(updateFilter);
+      tone1=tone2;
+    }
+    chgMsec = 0;
+  }
+}
+

examples/SGTL5000_Specific/CalcBiquadToneControlDAP/CalcBiquadToneControlDAP.ino

+// Tone example using SGTL5000 DAP PEQ filters and calcBiquad filter calculator routine.
+
+#include <Audio.h>
+#include <Wire.h>
+#include <SD.h>
+
+const int myInput = AUDIO_INPUT_LINEIN;
+// const int myInput = AUDIO_INPUT_MIC;
+
+int updateFilter[5];
+ 
+AudioInputI2S        audioInput;         // audio shield: mic or line-in
+AudioOutputI2S       audioOutput;        // audio shield: headphones & line-out
+
+// Create Audio connections between the components
+//
+AudioConnection c1(audioInput, 0, audioOutput, 0); // left passing through
+AudioConnection c2(audioInput, 1, audioOutput, 1); // right passing through
+
+// Create an object to control the audio shield.
+// 
+AudioControlSGTL5000 audioShield;
+
+void setup() {
+  // Audio connections require memory to work.  For more
+  // detailed information, see the MemoryAndCpuUsage example
+  AudioMemory(4);
+  // Enable the audio shield, select the input and set the output volume.
+  audioShield.enable();
+  audioShield.inputSelect(myInput);
+  audioShield.volume(75);
+  audioShield.unmuteLineout();
+  audioShield.dap_enable(); // enable the DAP block in SGTL5000
+  audioShield.dap_audio_eq(1); // using PEQ Biquad filters
+  audioShield.dap_peqs(2); // enable filter 0 & filter 1
+
+  calcBiquad(FILTER_PARAEQ,110,0,0.2,524288,44100,updateFilter);
+  audioShield.load_peq(0,updateFilter);
+  calcBiquad(FILTER_PARAEQ,4400,0,0.167,524288,44100,updateFilter);
+  audioShield.load_peq(1,updateFilter);
+}
+
+elapsedMillis chgMsec=0;
+float tone1=0;
+
+void loop() {
+  // every 10 ms, check for adjustment the tone & vol
+  if (chgMsec > 10) { // more regular updates for actual changes seems better.
+    
+    float tone2=analogRead(15);
+    tone2=floor(((tone2-512)/512)*70)/10;
+    if(tone2!=tone1)
+    {
+      // calcBiquad(FilterType,FrequencyC,dBgain,Q,QuantizationUnit,SampleRate,int*);
+      calcBiquad(FILTER_PARAEQ,110,-tone2,0.2,524288,44100,updateFilter);
+      audioShield.load_peq(0,updateFilter);
+      calcBiquad(FILTER_PARAEQ,4400,tone2,0.167,524288,44100,updateFilter);
+      audioShield.load_peq(1,updateFilter);
+      tone1=tone2;
+    }
+    chgMsec = 0;
+  }
+}
+

examples/SGTL5000_Specific/balanceDAC/balanceDAC.ino

 #include <Wire.h>
 #include <SD.h>
 
-#define PIN_VOLUME 0
-#define PIN_BALANCE 15
 
 const int myInput = AUDIO_INPUT_LINEIN;
 // const int myInput = AUDIO_INPUT_MIC;
 AudioInputI2S       audioInput;         // audio shield: mic or line-in
 AudioOutputI2S      audioOutput;        // audio shield: headphones & line-out
 
-
-
 // Create Audio connections between the components
 //
 AudioConnection c1(audioInput, 0, audioOutput, 0); // left passing through
 void setup() {
   // Audio connections require memory to work.  For more
   // detailed information, see the MemoryAndCpuUsage example
-  AudioMemory(6);
+  AudioMemory(4);
   // Enable the audio shield and set the output volume.
   audioShield.enable();
   audioShield.inputSelect(myInput);
-  audioShield.volume(90);
+  audioShield.volume(75);
   audioShield.unmuteLineout();
 }
 
 elapsedMillis chgMsec=0;
-float lastVol=1024;
 float lastBal=1024;
 
 void loop() {
   // every 10 ms, check for adjustment the balance & vol
   if (chgMsec > 10) { // more regular updates for actual changes seems better.
-#if PIN_BALANCE
-    float bal1=analogRead(PIN_BALANCE);
-#else
-    float bal1=0; // middle will be default if analog pin is not supplied
-#endif
+    float bal1=analogRead(15);
     bal1=((bal1-512)/512)*100;
     bal1=(int)bal1;
     if(lastBal!=bal1)
       }
       lastBal=bal1;
     }
-
-#if PIN_VOLUME
-    float vol1=analogRead(PIN_VOLUME)/10.23; // 0 - 100
-#else
-    float vol1=70; // 70% output will be default if analog pin is not supplied.
-#endif
-    vol1=(int)vol1;
-    if(lastVol!=vol1)
-    {
-      audioShield.volume(vol1);
-      lastVol=vol1;
-    }
     chgMsec = 0;
   }
 }

examples/SGTL5000_Specific/balanceHP/balanceHP.ino

-// HP balance example: Will influence both HP & LO outputs.
+// HP balance example: Will influence only HP output.
 
 #include <Audio.h>
 #include <Wire.h>
 #include <SD.h>
 
-#define PIN_VOLUME 0
-#define PIN_BALANCE 15
-
 const int myInput = AUDIO_INPUT_LINEIN;
 // const int myInput = AUDIO_INPUT_MIC;
 
 AudioInputI2S       audioInput;         // audio shield: mic or line-in
 AudioOutputI2S      audioOutput;        // audio shield: headphones & line-out
 
-
-
 // Create Audio connections between the components
 
 // Just connecting in to out
 void setup() {
   // Audio connections require memory to work.  For more
   // detailed information, see the MemoryAndCpuUsage example
-  AudioMemory(12);
+  AudioMemory(4);
   // Enable the audio shield and set the output volume.
   audioShield.enable();
   audioShield.inputSelect(myInput);
 
 elapsedMillis chgMsec=0;
 
-float lastVol=1024;
 float lastBal=1024;
+float vol1=75;
 
 void loop() {
   // every 10 ms, check for adjustment the balance & vol
   if (chgMsec > 10) { // more regular updates for actual changes seems better.
-
-#if PIN_VOLUME
-    float vol1=analogRead(PIN_VOLUME)/10.23; // 0 - 1000
-#else
-    float vol1=70; // 70% output will be default if analog pin is not supplied.
-#endif
-    vol1=(int)vol1;
-
-#if PIN_BALANCE
-    float bal1=analogRead(PIN_BALANCE);
-#else
-    float bal1=0; // middle will be default if analog pin is not supplied
-#endif
+    float bal1=analogRead(15);
     bal1=((bal1-512)/512)*100;
     bal1=(int)bal1;
-    if((lastVol!=vol1)||(lastBal!=bal1))
+    if(lastBal!=bal1)
     {
       if(bal1<0)
       {
       } else {
         audioShield.volume((vol1/100)*(100-bal1),vol1);
       }
-      lastVol=vol1;
       lastBal=bal1;
     }
     chgMsec = 0;