Update the PlaySynthMusic example to use a floating point table of note frequencies (not divided by 2)

examples/PlaySynthMusic/PlaySynthMusic.h

@@ -4,6 +4,7 @@
 //   Generated from Excel by =ROUND(2*440/32*(2^((x-9)/12)),0) for 0<x<128
 // The lowest notes might not work, depending on the Arduino clock frequency
 
+#ifdef ORIGINAL_TABLE
 const unsigned int tune_frequencies2_PGM[128] =
 {
     16,17,18,19,21,22,23,24,26,28,29,31,33,35,37,39,41,
@@ -18,7 +19,29 @@ const unsigned int tune_frequencies2_PGM[128] =
     13290,14080,14917,15804,16744,17740,18795,19912,21096,
     22351,23680,25088
 };
-
+#else
+// This is for the Teensy Audio library which specifies
+// frequencies as floating point. See make_notetab.xlsx
+const float tune_frequencies2_PGM[128] =
+{
+    8.1758,    8.6620,    9.1770,    9.7227,    10.3009,    10.9134,    11.5623,    12.2499,
+    12.9783,   13.7500,   14.5676,   15.4339,   16.3516,    17.3239,    18.3540,    19.4454,
+    20.6017,   21.8268,   23.1247,   24.4997,   25.9565,    27.5000,    29.1352,    30.8677,
+    32.7032,   34.6478,   36.7081,   38.8909,   41.2034,    43.6535,    46.2493,    48.9994,
+    51.9131,   55.0000,   58.2705,   61.7354,   65.4064,    69.2957,    73.4162,    77.7817,
+    82.4069,   87.3071,   92.4986,   97.9989,   103.8262,   110.0000,   116.5409,   123.4708,
+    130.8128,  138.5913,  146.8324,  155.5635,  164.8138,   174.6141,   184.9972,   195.9977,
+    207.6523,  220.0000,  233.0819,  246.9417,  261.6256,   277.1826,   293.6648,   311.1270,
+    329.6276,  349.2282,  369.9944,  391.9954,  415.3047,   440.0000,   466.1638,   493.8833,
+    523.2511,  554.3653,  587.3295,  622.2540,  659.2551,   698.4565,   739.9888,   783.9909,
+    830.6094,  880.0000,  932.3275,  987.7666,  1046.5023,  1108.7305,  1174.6591,  1244.5079,
+    1318.5102, 1396.9129, 1479.9777, 1567.9817, 1661.2188,  1760.0000,  1864.6550,  1975.5332,
+    2093.0045, 2217.4610, 2349.3181, 2489.0159, 2637.0205,  2793.8259,  2959.9554,  3135.9635,
+    3322.4376, 3520.0000, 3729.3101, 3951.0664, 4186.0090,  4434.9221,  4698.6363,  4978.0317,
+    5274.0409, 5587.6517, 5919.9108, 6271.9270, 6644.8752,  7040.0000,  7458.6202,  7902.1328,
+    8372.0181, 8869.8442, 9397.2726, 9956.0635, 10548.0818, 11175.3034, 11839.8215, 12543.8540
+};
+#endif
 
 #define CMD_PLAYNOTE	0x90	/* play a note: low nibble is generator #, note is next byte */
 #define CMD_STOPNOTE	0x80	/* stop a note: low nibble is generator # */

examples/PlaySynthMusic/PlaySynthMusic.ino

@@ -1,7 +1,6 @@
 // Implement the midi player inside the Audio library.
 // This uses the new version of the waveform generator code
 // See PlayMidiTones for code which uses the old version
-
  
 #include <Audio.h>
 #include <Wire.h>
@@ -38,46 +37,57 @@ AudioSynthWaveform *waves[8] = {
   &sine7,
 };
 
+// allocate a wave type to each channel.
+// The types used and their order is purely arbitrary.
+short wave_type[8] = {
+  TONE_TYPE_SINE,
+  TONE_TYPE_SQUARE,
+  TONE_TYPE_SAWTOOTH,
+  TONE_TYPE_TRIANGLE,
+  TONE_TYPE_SINE,
+  TONE_TYPE_SQUARE,
+  TONE_TYPE_SAWTOOTH,
+  TONE_TYPE_TRIANGLE,
+};
+
+// Two mixers are needed to handle the 8 channels of music
 AudioMixer4              mixer1;
 AudioMixer4              mixer2;
 AudioOutputI2S audioOut;
 
+// Mix the first four channels into mixer1
 AudioConnection c0(sine0, 0, mixer1, 0);
 AudioConnection c1(sine1, 0, mixer1, 1);
 AudioConnection c2(sine2, 0, mixer1, 2);
 AudioConnection c3(sine3, 0, mixer1, 3);
 
+// and the last 4 channels into mixer2
 AudioConnection c4(sine4, 0, mixer2, 0);
 AudioConnection c5(sine5, 0, mixer2, 1);
 AudioConnection c6(sine6, 0, mixer2, 2);
 AudioConnection c7(sine7, 0, mixer2, 3);
+
+// Output mixre1 to the left channel and mixer2 to the right
 AudioConnection c11(mixer1, 0, audioOut, 0);
 AudioConnection c12(mixer2, 0, audioOut, 1);
 
 //AudioControl_WM8731 codec;
 AudioControlSGTL5000 codec;
 
+// Initial value of the volume control
 int volume = 50;
 
-// allocate a wave type to each channel.
-// The types used and their order is purely arbitrary.
-short wave_type[8] = {
-  TONE_TYPE_SINE,
-  TONE_TYPE_SQUARE,
-  TONE_TYPE_SAWTOOTH,
-  TONE_TYPE_TRIANGLE,
-  TONE_TYPE_SINE,
-  TONE_TYPE_SQUARE,
-  TONE_TYPE_SAWTOOTH,
-  TONE_TYPE_TRIANGLE,
-};
-
 void setup()
 {
   Serial.begin(115200);
   while (!Serial) ;
-  delay(3000);
-
+  delay(2000);
+  
+// http://gcc.gnu.org/onlinedocs/cpp/Standard-Predefined-Macros.html
+  Serial.print("Begin ");
+  Serial.println(__FILE__);
+  
+  // Proc = 12 (13),  Mem = 2 (8)
   // Audio connections require memory to work.
   // The memory usage code indicates that 8 is the maximum
   // so give it 10 just to be sure.
@@ -89,14 +99,11 @@ void setup()
   // Comment this if you don't it
   codec.unmuteLineout();
 
-  
   // Set the ramp time for each wave object
   for(int i = 0; i < 8;i++) {
     waves[i]->set_ramp_length(88);
   }
 
-  Serial.println("Begin PlayMidiTones");
-
   Serial.println("setup done");
   
   // Initialize processor and memory measurements
@@ -111,8 +118,8 @@ void loop()
   unsigned char c,opcode,chan;
   unsigned long d_time;
   
-// Change this to if(1) for measurement output
-if(0) {
+// Change this to if(1) for measurement output every 5 seconds
+if(1) {
 /*
   For PlaySynthMusic this produces:
   Proc = 20 (21),  Mem = 2 (8)
@@ -138,6 +145,7 @@ if(0) {
     codec.volume((float)n / 10.23);
   }
   
+  // read the next note from the table
   c = *sp++;
   opcode = c & 0xf0;
   // was 0x0f but I'm only handling 8 channels
@@ -163,7 +171,8 @@ if(0) {
     return;
   }
   
-  // Play the note on 'chan'
+  // Play the note on 'chan' - divide the frequency by two because the
+  // table of frequencies has been doubled.
   if(opcode == CMD_PLAYNOTE) {
     waves[chan]->begin(AMPLITUDE,tune_frequencies2_PGM[*sp++],
                         wave_type[chan]);