#define CP33_CHANNEL           0
#define CP33_BANK_DEFAULT      0
#define VELOCITY_FFF         127
#define MIDI_CHAN_BANK      0x00
#define MIDI_CHAN_VOLUME    0x07
#define MIDI_CHAN_MSG       0xB0
#define MIDI_CHAN_PROGRAM   0xC0

void setup()
{
	// MIDIチャンネル指定
	Serial1.write(MIDI_CHAN_MSG | CP33_CHANNEL);
	Serial1.write((uint8_t)MIDI_CHAN_BANK);
	Serial1.write((uint8_t)CP33_BANK_DEFAULT);

	// 音量指定
	Serial1.write(MIDI_CHAN_MSG | CP33_CHANNEL);
	Serial1.write(MIDI_CHAN_VOLUME);
	Serial1.write(VELOCITY_FFF);

	// ボイス指定
	Serial1.write(MIDI_CHAN_MSG | CP33_CHANNEL);
	Serial1.write((uint8_t)0x00);
	Serial1.write((uint8_t)0x00);
	Serial1.write(MIDI_CHAN_MSG | CP33_CHANNEL);
	Serial1.write(0x20);
	Serial1.write(123);
	Serial1.write(MIDI_CHAN_PROGRAM | CP33_CHANNEL);
	Serial1.write(1);

	// サンプリング 21(A0) ～ 108(C8)
	for(int noteNo = 21;noteNo<=108;noteNo++) {
		Serial1.write(0x90);   // note on
		Serial1.write(noteNo);
		Serial1.write(127);
		delay(500);
		Serial1.write(0x80);   // note off
		Serial1.write(noteNo);
		Serial1.write(127);
		delay(200);
	}
}

void loop() {}

#include <Arduino.h>
#include <SPI.h>
#include <FS.h>
#include <SD.h>

#define SD_CS   A3
#define SDSPEED 40000000

// The Canonical WAVE file format
typedef struct {
	uint8_t  ChunkID[4];
	uint32_t ChunkSize;
	uint8_t  Format[4];
	uint8_t  Subchunk1ID[4];
	uint32_t Subchunk1Size;
	uint16_t AudioFormat;
	uint16_t NumChannels;
	uint32_t SampleRate;
	uint32_t ByteRate;
	uint16_t BlockAlign;
	uint16_t BitPerSample;
	uint8_t  Subchunk2ID[4];
	uint32_t Subchunk2Size;
	int16_t  *wavdata;
} WAV_FORMAT;

#define SAMPLING_RATE 44100
#define WAVDATA_SIZE  52920   // 44100x0.6x2
#define BLOCK_SIZE    61740

File file;

boolean getWavFormat(WAV_FORMAT *pwf) {

	long len;
	short cbsize;

	if (file.read((uint8_t *)pwf,20) == -1) {
		Serial1.println("file.read() error");
		return false;
	}
	if (memcmp(pwf->Subchunk1ID,"fmt ",4)==0) {
		if((len = file.read((uint8_t *)pwf+20,24))==-1) return false;
	} else if (memcmp(pwf->Subchunk1ID,"LIST",4)==0) {
		if (file.seek(20+pwf->Subchunk1Size)) {
			if((len = file.read((uint8_t *)pwf+12,24))==-1) return false;
			if (pwf->Subchunk1Size == 18) {
				// skip cbsize on WAVEFORMATEX
				if((len = file.read((uint8_t *)&cbsize,2))==-1) return false;
			}
			if((len = file.read((uint8_t *)pwf+36,8))==-1) return false;
		} else {
			return false;
		}
	} else {
		return false;
	}
	if(  memcmp(pwf->ChunkID,     "RIFF", 4)
	   ||memcmp(pwf->Format,      "WAVE", 4)
	   ||memcmp(pwf->Subchunk1ID, "fmt ", 4)
	   ||memcmp(pwf->Subchunk2ID, "data", 4))
	     return false;
	else return true;
}

void setup() {

	char  noteStr[4];
	char  noteFileName[22];
	long  file_pos, pos, len;
	int16_t max_amplitude_A0, max_amplitude;
	float    factor;

	WAV_FORMAT *pwf;

	SD.begin( SD_CS, SPI, SDSPEED);

	pwf = (WAV_FORMAT *)malloc(sizeof(WAV_FORMAT));
	pwf->wavdata = (int16_t *)malloc(WAVDATA_SIZE));

	for(int noteNo = 21;noteNo<=108;noteNo++) {

		int octave = ((int)(noteNo/12) -1 + 0x30);
		memset(¬eStr, 0x00, 4);
		switch(noteNo%12) {
			case  0: noteStr[0] = 'C'; noteStr[1] = octave;                   break;
			case  1: noteStr[0] = 'C'; noteStr[1] = octave; noteStr[2] = '#'; break;
			case  2: noteStr[0] = 'D'; noteStr[1] = octave;                   break;
			case  3: noteStr[0] = 'D'; noteStr[1] = octave; noteStr[2] = '#'; break;
			case  4: noteStr[0] = 'E'; noteStr[1] = octave;                   break;
			case  5: noteStr[0] = 'F'; noteStr[1] = octave;                   break;
			case  6: noteStr[0] = 'F'; noteStr[1] = octave; noteStr[2] = '#'; break;
			case  7: noteStr[0] = 'G'; noteStr[1] = octave;                   break;
			case  8: noteStr[0] = 'G'; noteStr[1] = octave; noteStr[2] = '#'; break;
			case  9: noteStr[0] = 'A'; noteStr[1] = octave;                   break;
			case 10: noteStr[0] = 'A'; noteStr[1] = octave; noteStr[2] = '#'; break;
			case 11: noteStr[0] = 'B'; noteStr[1] = octave;                   break;
		}

		if (noteNo == 21) {
			if(file = SD.open("/mono_piano/mono_piano.wav")) {
				getWavFormat(pwf);
				pwf->Subchunk2Size = WAVDATA_SIZE;
				len = file.read((uint8_t*)pwf->wavdata,WAVDATA_SIZE);
				if (len == WAVDATA_SIZE) {
					max_amplitude_A0 = 0;
					for(pos = 0; pos < (WAVDATA_SIZE/2); pos++) {
						if (max_amplitude_A0 < pwf->wavdata[pos]) max_amplitude_A0 = pwf->wavdata[pos];
					}

					// 音割れするので振幅を縮小する
					factor = ((float)max_amplitude_A0 * 0.6) / max_amplitude_A0;
					max_amplitude_A0 = (float)max_amplitude_A0 * 0.4;
					for(pos = 0; pos < (WAVDATA_SIZE/2); pos++) {
						pwf->wavdata[pos] = (int16_t)(factor * (float)pwf->wavdata[pos]);
					}
					file_pos = 44 + BLOCK_SIZE;
				}
				file.close();
			}
		} else {
			if(file = SD.open("/mono_piano/mono_piano.wav")) {
				file.seek(file_pos);
				len = file.read((uint8_t*)pwf->wavdata,WAVDATA_SIZE);
				if (len == WAVDATA_SIZE) {
					max_amplitude = 0;
					for(pos = 0; pos < (WAVDATA_SIZE/2); pos++) {
						if (max_amplitude < pwf->wavdata[pos]) max_amplitude = pwf->wavdata[pos];
					}
					factor = (float)max_amplitude_A0 / (float)max_amplitude;
					for(pos = 0; pos < (WAVDATA_SIZE/2); pos++) {
						pwf->wavdata[pos] = (int16_t)(factor * (float)pwf->wavdata[pos]);
					}
					file_pos += BLOCK_SIZE;
				}
				file.close();
			}
		}

		sprintf(noteFileName,"/mono_piano/%s.wav",noteStr);
		if(file = SD.open(noteFileName,FILE_WRITE)) {
			file.write((uint8_t*)pwf,44);
			file.write((uint8_t*)pwf->wavdata,(size_t)WAVDATA_SIZE);
			file.close();
		}
	}
}

void loop() {}