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libraries/audio-tools/examples/examples-stream/streams-generator_fromarray-analog/README.md

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+# I2S Analog Output Test
+
+This is a simple basic test for the ESP32 __analog output__ using I2S.
+
+We just send a generated sine wave and expect to hear a clean signal.
+Please note the log level should be set so that there is no disturbing output!
+
+ 
+### Output Device: Piezo Electric Element
+
+To test the output I am using a piezo electric element
+
+![DAC](https://pschatzmann.github.io/Resources/img/piezo.jpeg)
+
+It should also be possible to connect a headphone to the output pins...
+
+
+On the ESP32 the output is on the Pins GPIO26 and GPIO27
+
+| PIEZO     |  ESP32
+| --------| ---------------
+| +       |  GPIO25 / GPIO26
+| -       |  GND
+
+

libraries/audio-tools/examples/examples-stream/streams-generator_fromarray-analog/streams-generator_fromarray-analog.ino

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+/**
+ * @file streams-generator_fromarray-analog.ino
+ * @author Phil Schatzmann
+ * @brief Example for GeneratorFromArray
+ * @version 0.1
+ * @date 2022-03-22
+ * 
+ * @copyright Copyright (c) 2022
+ * 
+ */
+#include "AudioTools.h"
+#include "AudioTools/AudioLibs/AudioBoardStream.h"
+
+AudioInfo info(44100, 1, 16);
+int16_t sine_array[] = {0, 4560, 9031, 13327, 17363, 21062, 24350, 27165, 29450, 31163, 32269, 32747, 32587, 31793, 30381, 28377, 25820, 22761, 19259, 15383, 11206, 6812, 2285, -2285, -6812, -11206, -15383, -19259, -22761, -25820, -28377, -30381, -31793, -32587, -32747, -32269, -31163, -29450, -27165, -24350, -21062, -17363, -13327, -9031, -4560  };
+GeneratorFromArray<int16_t> sineWave(sine_array,0,false);
+GeneratedSoundStream<int16_t> sound(sineWave);             // Stream generated from sine wave
+AnalogAudioStream out; 
+StreamCopy copier(out, sound);                             // copies sound into i2s
+
+// Arduino Setup
+void setup(void) {  
+  // Open Serial 
+  Serial.begin(115200);
+  AudioToolsLogger.begin(Serial, AudioToolsLogLevel::Warning);
+
+  // start I2S
+  Serial.println("starting I2S...");
+  auto config = out.defaultConfig(TX_MODE);
+  config.copyFrom(info); 
+  out.begin(config);
+
+  // Setup sine wave
+  sineWave.begin(info);
+  Serial.println("started...");
+}
+
+// Arduino loop - copy sound to out 
+void loop() {
+  copier.copy();
+}