82 lines
1.9 KiB
C++
Executable File
82 lines
1.9 KiB
C++
Executable File
#ifndef GOERTZEL_H
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#define GOERTZEL_H
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/*
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Goertzel formula audio detector
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This code comes from http://www.skovholm.com/cwdecoder , http://www.skovholm.com/decoder11.ino
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Hjalmar skovholm Hansen, OZ1JHM <hjh@skovholm.com>
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Notes from the original code author, OZ1JHM (with edits from Goody K3NG)
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GOERTZ_SAMPLING_FREQ will be 8928 on a 16 mhz without any prescaler etc.
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because we need the tone in the center of the bins
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you can set GOERTZ_TARGET_FREQ (the tone) to 496, 558, 744 or 992
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then GOERTZ_SAMPLES_INT the number of samples which give the bandwidth
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which can be (8928 / GOERTZ_TARGET_FREQ) * 1 or 2 or 3 or 4 etc
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init is 8928/558 = 16 * 4 = 64 samples
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try to take GOERTZ_SAMPLES = 96 or 128 ;o)
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48 will give you a bandwidth around 186 hz
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64 will give you a bandwidth around 140 hz
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96 will give you a bandwidth around 94 hz
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128 will give you a bandwidth around 70 hz
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BUT remember that a high GOERTZ_SAMPLES will take a lot of time so you have to find a compromise
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*/
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#if defined(_VARIANT_ARDUINO_DUE_X_)
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// Arduino Due (84 Mhz clock)
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#define GOERTZ_SAMPLING_FREQ 46872.0
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#define GOERTZ_SAMPLES 252 //168 //84
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#else
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// Arduino Uno, Mega (16 Mhz clock)
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#define GOERTZ_SAMPLING_FREQ 8928.0
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#define GOERTZ_SAMPLES 48 //48 //64
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#endif
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#define GOERTZ_NOISE_BLANKER_INITIAL_MS 6
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#define GOERTZ_TARGET_FREQ 558.0
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#define GOERTZ_MAGNITUDE_LIMIT_LOW 100
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#define GOERTZ_MAGNITUDE_THRESHOLD 0.6 //0.6
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#define GOERTZ_MOVING_AVERAGE_FILTER 6
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class Goertzdetector {
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public:
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Goertzdetector();
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void init(int _audioInPin);
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int detecttone();
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int testData[GOERTZ_SAMPLES];
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float magnitude;
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int magnitudelimit;
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int magnitudelimit_low;
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private:
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float coeff;
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float Q1;
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float Q2;
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float sine;
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float cosine;
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int audioInPin;
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int realstate;
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int realstatebefore;
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int filteredstate;
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unsigned long laststarttime;
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};
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#endif //GOERTZEL_H
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