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libraries/audio-tools/examples/examples-stream/streams-memory_wav-pwm/README.md

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+# Decoding a WAV file
+
+In this example we decode a WAV file into RAW output and send it to a PWM pins (on a Raspberry Pico or ESP32)
+
+The WAV file has been down sampled with the help of __Audacity__ and then converted into an array with __xxd__. 
+
+Please note that this example is still using the more confusing old api which uses the following processing chain:
+MemoryStream -> AudioOutputStream -> WAVDecoder -> AudioPWM 
+
+
+The pins depend on the Processor:
+
+| PIEZO   |  ESP32       | RPI Pico      | MBED         |
+| --------| -------------|---------------|--------------|
+| +       |  GPIO4       | GPIO2         | GPIO2        |
+| -       |  GND         |               |              |
+
+
+Complie with Partition Scheme Huge APP!

libraries/audio-tools/examples/examples-stream/streams-memory_wav-pwm/streams-memory_wav-pwm.ino

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+/**
+ * @file stream-memory_wav-pwm.ino
+ * @author Phil Schatzmann
+ * @brief decode WAV stream and output to PWM pins
+ * @version 0.1
+ * @date 2021-01-24
+ * 
+ * @copyright Copyright (c) 2021
+ */
+
+#include "AudioTools.h"
+//#include "knghtsng.h"
+#include "alice.h"
+
+//Data Flow: MemoryStream -> EncodedAudioStream  -> PWMAudioOutput
+//Use 8000 for alice_wav and 11025 for knghtsng_wav
+AudioInfo info(8000, 1, 16);
+//MemoryStream wav(knghtsng_wav, knghtsng_wav_len);
+MemoryStream wav(alice_wav, alice_wav_len);
+PWMAudioOutput pwm;          // PWM output 
+EncodedAudioStream out(&pwm, new WAVDecoder()); // Decoder stream
+StreamCopy copier(out, wav);    // copy in to out
+
+void setup(){
+  Serial.begin(115200);
+  AudioToolsLogger.begin(Serial, AudioToolsLogLevel::Info);  
+
+  wav.begin();
+  out.begin();
+
+  auto config = pwm.defaultConfig();
+  config.copyFrom(info);
+  pwm.begin(config);
+}
+
+void loop(){
+  if (wav) {
+    copier.copy();
+  } else {
+    // after we are done we just print some info form the wav file
+    auto info = out.audioInfo();
+    LOGI("The audio rate from the wav file is %d", info.sample_rate);
+    LOGI("The channels from the wav file is %d", info.channels);
+
+    // restart from the beginning
+    Serial.println("Restarting...");
+    delay(5000);
+    out.begin();   // indicate that we process the WAV header
+    wav.begin();       // reset actual position to 0
+    pwm.begin();       // reset counters 
+  }
+}