Output via Callback and Output to Arduino Stream

README.md

@@ -5,9 +5,11 @@ View this project on [CADLAB.io](https://cadlab.io/project/1281).
 ## Text-to-Speech Library for Arduino
 
 - checkout this project into your ``sketchbook/libraries`` folder
-- requires an amplifier on the PWM output pin (see below)
+- requires an amplifier on the PWM output pin (see below) 
+- alternative output via Stream or callback method
 - see [blog articles](http://programmablehardware.blogspot.ie/search/label/tts)
 
+
 ## Supported Hardware
 
 - ATmega328-based Arduinos (e.g., Uno, Pro, Pro Mini, etc.): pins 3, 9, 10
@@ -43,3 +45,4 @@ and ARM processors with DAC (Teensy, Due)
 - Teensy [forum](https://forum.pjrc.com/threads/44587-TTS-(Text-to-Speech)-Library-Port)
 - separate port/hack for MBED ARM with DAC [repository](https://developer.mbed.org/users/manitou/code/tts/)
 - Hackaday article on [LM386 amplifiers](https://hackaday.com/2016/12/07/you-can-have-my-lm386s-when-you-pry-them-from-my-cold-dead-hands/)
+- Example on how to use the [Output via Streams](https://www.pschatzmann.ch/home/2021/06/22/text-to-speach-in-arduino-using-tts/) 

TTS.cpp

@@ -16,7 +16,6 @@
 
 #include "TTS.h"
 #include "english.h"
-#include "sound.h"
 
 #define NUM_VOCAB sizeof(s_vocab)/sizeof(VOCAB)
 #define NUM_PHONEME sizeof(s_phonemes)/sizeof(PHONEME)
@@ -29,6 +28,7 @@ static byte seed2;
 static char phonemes[128];
 static char modifier[sizeof(phonemes)];	// must be same size as 'phonemes'
 
+
 // Lookup user specified pitch changes
 static const byte PROGMEM PitchesP[] = { 1, 2, 4, 6, 8, 10, 13, 16 };
 
@@ -319,39 +319,61 @@ static byte random2(void)
     return seed0;
 }
 
-static byte playTone(int pin, byte soundNum, byte soundPos, char pitch1, char pitch2, byte count, byte volume)
+byte TTS::playTone(byte soundNum, byte soundPos, char pitch1, char pitch2, byte count, byte volume)
 {
     const byte *soundData = &SoundData[soundNum * 0x40];
     while (count-- > 0) {
 	byte s = pgm_read_byte(&soundData[soundPos & 0x3fu]);
-	sound(pin, s & volume);
+	sound_api->sound(s & volume);
 	pause(pitch1);
-	sound(pin, (s >> 4) & volume);
+	sound_api->sound((s >> 4) & volume);
 	pause(pitch2);
 
 	soundPos++;
     }
     return soundPos & 0x3fu;
 }
 
-static void play(int pin, byte duration, byte soundNumber)
+void TTS::play(byte duration, byte soundNumber)
 {
     while (duration--)
-	playTone(pin, soundNumber, random2(), 7, 7, 10, 15);
+	playTone(soundNumber, random2(), 7, 7, 10, 15);
 }
 
 /******************************************************************************
  * User API
  ******************************************************************************/
+
+
 TTS::TTS(int p)
 {
-    pin = p;
+	sound_api = new Sound(p);
     defaultPitch = 7;
+	stream_ptr = nullptr;         
 #ifdef __AVR__
     pinMode(pin, OUTPUT);
 #endif
 }
 
+TTS::TTS(tts_data_callback_type cb, int len) {
+	sound_api = new SoundCallback(cb, this, len);
+	defaultPitch = 7;
+	stream_ptr = nullptr;         
+}
+
+/**
+	* @brief Construct a new TTS object which outputs the data to an Arduino Stream
+	* 
+	* @param out 
+	*/
+TTS::TTS(Print &out, int bits_per_sample) { 
+	stream_ptr = &out;         
+	sound_api = new SoundCallback((tts_data_callback_type)TTS::stream_data_callback, this, 512);
+	defaultPitch = 7;
+	getInfo().bits_per_sample = bits_per_sample;
+}
+
+
 /*
  * Speak a string of phonemes
  */
@@ -373,7 +395,7 @@ void TTS::sayPhonemes(const char *textp)
 
     if (phonemesToData(textp, s_phonemes)) {
 	// phonemes has list of sound bytes
-	soundOn(pin);
+	sound_api->soundOn();
 
 	// initialise random number seed
 	seed0 = 0xecu;
@@ -435,7 +457,7 @@ void TTS::sayPhonemes(const char *textp)
 			// Make a white noise sound!
 			byte volume = (duration == 6) ? 15 : 1;	// volume mask
 			for (duration <<= 2; duration > 0; duration--) {
-			    playTone(pin, sound1Num, random2(), 8, 12, 11, volume);
+			    playTone(sound1Num, random2(), 8, 12, 11, volume);
 			    // Increase the volume
 			    if (++volume == 16)
 				volume = 15;	// full volume from now on
@@ -502,11 +524,11 @@ void TTS::sayPhonemes(const char *textp)
 		byte sound1End = min(sound1Stop, sound2Stop);
 
 		if (sound1Stop)
-		    soundPos = playTone(pin, sound1Num, soundPos, pitch1, pitch1, sound1End, 15);
+		    soundPos = playTone(sound1Num, soundPos, pitch1, pitch1, sound1End, 15);
 
 		// s18
 		if (sound2Stop != 0x40) {
-		    soundPos = playTone(pin, sound2Num, soundPos, pitch2, pitch2, sound2Stop - sound1End, 15);
+		    soundPos = playTone(sound2Num, soundPos, pitch2, pitch2, sound2Stop - sound1End, 15);
 		}
 		// s23
 		if (sound1Duration != 0xff && duration < byte2) {
@@ -517,13 +539,13 @@ void TTS::sayPhonemes(const char *textp)
 		}
 		// Call any additional sound
 		if (byte1 == -1)
-		    play(pin, 3, 30);	// make an 'f' sound
+		    play(3, 30);	// make an 'f' sound
 		else if (byte1 == -2)
-		    play(pin, 3, 29);	// make an 's' sound
+		    play(3, 29);	// make an 's' sound
 		else if (byte1 == -3)
-		    play(pin, 3, 33);	// make a 'th' sound
+		    play(3, 33);	// make a 'th' sound
 		else if (byte1 == -4)
-		    play(pin, 3, 27);	// make a 'sh' sound
+		    play(3, 27);	// make a 'sh' sound
 
 	    } while (--duration);
 
@@ -543,7 +565,7 @@ void TTS::sayPhonemes(const char *textp)
 		delay2(25);
 	}			// next phoneme
     }
-    soundOff(pin);
+    sound_api->soundOff();
 }
 
 /*
@@ -556,3 +578,7 @@ void TTS::sayText(const char *original)
     if (textToPhonemes(original, s_vocab, text))
 	sayPhonemes(text);
 }
+
+
+
+

TTS.h

@@ -13,12 +13,56 @@
 
 #ifndef _TTS_H_
 #define _TTS_H_
+#include "sound.h"
+
+/**
+ * @brief TTS Output Information 
+ * 
+ */
+struct TTSInfo {
+  int channels = 1;
+  int sample_rate = 12000;
+  int bits_per_sample = 8;
+};
+
+/**
+ * @brief TTS API
+ * 
+ */
 
 class TTS {
   public:
-
+    /**
+     * @brief Construct a new TTS object using the default pin
+     * 
+     */
     TTS(int pin);
 
+
+    /**
+     * @brief Construct a new TTS object - Uses the Callback to provide the result
+     * 
+     */
+    TTS(tts_data_callback_type cb, int len=512);
+
+    /**
+     * @brief Construct a new TTS object which outputs the data to an Arduino Stream
+     * 
+     * @param out 
+     */
+    TTS(Print &out, int bits_per_sample=16);
+
+    /**
+     * @brief Destroy the TTS object
+     * 
+     */
+    ~TTS(){
+      if(sound_api!=nullptr) {
+        delete sound_api;
+      }
+    }
+
+
     /**
      * speaks a string of (english) text
      */
@@ -39,9 +83,47 @@ class TTS {
      */
     byte getPitch(void) { return defaultPitch; }
 
-  private:
+    /**
+     * @brief Get additional output information
+     * 
+     * @return TTSInfo 
+     */
+    static TTSInfo& getInfo() {
+      static TTSInfo info;
+      return info;
+    }
+
+    // allow callback to access private fields
+    friend void stream_data_callback(void *vtts, int len, byte *data);
+
+  protected:
     byte defaultPitch;
-    int pin;
+    BaseSound *sound_api = nullptr;
+    Print *stream_ptr = nullptr;
+
+    void play(byte duration, byte soundNumber);
+    byte playTone(byte soundNum, byte soundPos, char pitch1, char pitch2, byte count, byte volume);
+
+    // callback to write sound data to stream
+    static void stream_data_callback(void *vtts, int len, byte *data){
+      TTS *tts = (TTS *) vtts;
+      TTSInfo *info = &getInfo();
+      if (tts->stream_ptr!=nullptr && len>0 && data!=nullptr){
+        if (info->bits_per_sample==8){
+          tts->stream_ptr->write((const char*)data, len);
+        } else {
+          // convert 8 to 16 bits
+          for (int j=0;j<len;j++){
+            int8_t sample = data[j];
+            int16_t sample16 = sample<<8;
+            tts->stream_ptr->write((const char*)&sample16, 2);
+          }
+        }
+      }
+    }
+
 };
 
+
+
 #endif

examples/Speak/Speak.ino

@@ -0,0 +1,22 @@
+
+/**
+ * @brief Simple example which should work on most environments
+ */
+
+#include "TTS.h"
+
+
+// TTS tts(3);  // with explicit pin
+TTS tts; // with default pin
+
+void setup(){
+  Serial.begin(115200);
+  // display pin
+  Serial.print("Using Pin ");
+  Serial.println(DEFAULT_PIN);
+}
+
+void loop(){
+    tts.sayText("hallo");
+    delay(5000);
+}

examples/SpeakWithCallback/SpeakWithCallback.ino

@@ -0,0 +1,22 @@
+/**
+ * @brief Example with Callback which just prints the result 
+ * 
+ */
+#include "TTS.h"
+
+void data_callback(int len, byte *data){
+    for (int j=0;j<len;j++){
+        Serial.println(data[j]);
+    }    
+}
+
+TTS tts(data_callback);
+
+void setup(){
+  Serial.begin(115200);
+}
+
+void loop(){
+    tts.sayText("hallo");
+    delay(5000);
+}

sound.cpp

@@ -6,7 +6,13 @@
 #define CHANNEL_FOR(p) (p == 25)? DAC_CHANNEL_1: DAC_CHANNEL_2
 #endif
 
-void soundOff(int pin)
+Sound::Sound(int pin)
+{
+    this->pin = pin;
+}
+
+
+void Sound::soundOff()
 {
 
 #if defined(__AVR__)
@@ -53,7 +59,7 @@ void soundOff(int pin)
 }
 
 //https://sites.google.com/site/qeewiki/books/avr-guide/pwm-on-the-atmega328
-void soundOn(int pin)
+void Sound::soundOn()
 {
 
 #if defined(__AVR__)
@@ -126,7 +132,7 @@ void soundOn(int pin)
 #endif
 }
 
-void sound(int pin, byte b)
+void Sound::sound(byte b)
 {
     // Update PWM volume
     b = (b & 15);
@@ -195,4 +201,27 @@ void sound(int pin, byte b)
 
     analogWrite(pin, b*8);
 #endif
+
+}
+
+void SoundCallback::soundOff(){
+    (*tts_callback)(tts, current_length, out_data);
+    memset(out_data,0, current_length);
+    current_length = 0;
+    active = false;
+}
+
+void SoundCallback::soundOn() {
+    active = true;
 }
+
+void SoundCallback::sound(byte b) {
+    out_data[current_length++] =  b ;
+    if (current_length>=max_length){
+        if (tts_callback!=nullptr) {
+            (*tts_callback)(tts, current_length, out_data);
+        }
+        memset(out_data, 0, current_length);
+        current_length = 0;
+    }
+}