Spectrum Serial Plotter

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1/*
2
3 This example reads audio data from an Invensense's ICS43432 I2S microphone
4
5 breakout board, and prints out the spectrum to the Serial console. The
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7 Serial Plotter built into the Arduino IDE can be used to plot the audio
8
9 amplitude data (Tools -> Serial Plotter)
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11 Circuit:
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13 * Arduino Zero, MKRZero or MKR1000 board
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15 * ICS43432:
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17   * GND connected GND
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19   * 3.3V connected 3.3V (Zero) or VCC (MKR1000, MKRZero)
20
21   * WS connected to pin 0 (Zero) or pin 3 (MKR1000, MKRZero)
22
23   * CLK connected to pin 1 (Zero) or pin 2 (MKR1000, MKRZero)
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25   * SD connected to pin 9 (Zero) or pin A6 (MKR1000, MKRZero)
26
27 created 21 November 2016
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29 by Sandeep Mistry
30
31 */
32
33#include <ArduinoSound.h>
34
35// sample rate for the input
36
37const int sampleRate = 8000;
38
39// size of the FFT to compute
40
41const int fftSize = 128;
42
43// size of the spectrum output, half of FFT size
44
45const int spectrumSize = fftSize / 2;
46
47// array to store spectrum output
48int spectrum[spectrumSize];
49
50// create an FFT analyzer to be used with the I2S input
51
52FFTAnalyzer fftAnalyzer(fftSize);
53
54void setup() {
55// Open serial communications and wait for port to open:
56
57  // A baud rate of 115200 is used instead of 9600 for a faster data rate
58
59  // on non-native USB ports
60
61  Serial.begin(115200);
62
63  while (!Serial) {
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65    ; // wait for serial port to connect. Needed for native USB port only
66
67  }
68
69  // setup the I2S audio input for the sample rate with 32-bits per sample
70
71  if (!AudioInI2S.begin(sampleRate, 32)) {
72
73    Serial.println("Failed to initialize I2S input!");
74
75    while (1); // do nothing
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77  }
78
79  // configure the I2S input as the input for the FFT analyzer
80
81  if (!fftAnalyzer.input(AudioInI2S)) {
82
83    Serial.println("Failed to set FFT analyzer input!");
84
85    while (1); // do nothing
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87  }
88}
89
90void loop() {
91
92  // check if a new analysis is available
93
94  if (fftAnalyzer.available()) {
95
96    // read the new spectrum
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98    fftAnalyzer.read(spectrum, spectrumSize);
99
100    // print out the spectrum
101
102    for (int i = 0; i < spectrumSize; i++) {
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104      Serial.print((i * sampleRate) / fftSize); // the starting frequency
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106      Serial.print("\t"); //
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108      Serial.println(spectrum[i]); // the spectrum value
109
110    }
111
112  }
113}